Questions about civics, diplomacy, improvements, etc.

[NFIH]

I have several questions regarding these issues. Any help is appreciated.

1. I notice that when I put some buildings in the queue, the hammer production goes up even if that building is not the actual item being built (e.g. it's second in line). The message is "100% hammers for collosseum by creative leader" or "100% for temple by spiritual leader." But the building isn't even built yet--it's merely in the queue. How does that work?

2. How does the AI adopt two different civics on the same turn? I see this all the time. I thought you could only change to one at a time. But I can't seem to do it. Instead I get the message, "can't change civics for five turns."

3. I'm not quite getting diplomacy in terms of how the AIs react to me. Specifically, I would say that about 99% of the time, I can't get an AI to go to war against someone else if I ask. This is even if I have "pleased" or "friendly" relations with them. What I don't get is, why is the option immediately redded out? I don't even have the option to offer something (cash, tech, etc.) so the AI can see whether it would be worth their while--and this is even if they're pleased or friendly toward me. In all the games I've played, I've only had the option to get someone to come on side with me maybe five times. Meanwhile, the AIs are asking me to go to war against someone pretty much every single turn (but they often don't actually declare war themselves!)--so much so that it gets quite tedious.

3a. There are also many situations where an AI asks you to declare war. If you say yes and ask on that same exchange for the AI to attack someone else in return, you only get the option to choose a particular city, not an entire empire. Why is that? Does it make more sense to decline the request to attack Y, then declare against Y on the next turn and then ask the AI to declare against my own target empire?

4. How do you manage your empire defence in the context of wildly unpredictable AI? For example, in my current game, I have "friendly" relations with Cyrus and we share the same religion. He has attacked me anyway. So how do you effectively defend against not only the people you know are hostile to you and could attack at any time and also "friends"? I would need a truly massive army (so that I have large forces on all fronts) to have a hope of responding adequately. And having a massive army itself doesn't appear to deter the AI from attacking, especially if that army is not right at the border with the potential AI enemy. Yes, I know about having mobile forces, but that usually isn't enough to prevent losing a city or two to an attack because, one, your units still need some travel time, and two, the AI frequently attacks on two or three fronts, not just one.

5. Is it generally better to upgrade existing units or buy new ones. Usually, I only upgrade when I need a quick emergency force to defend or I have lots of extra cash. But is this the most efficient approach?

6. When and where do you use windmills, watermills and lumbermills? I can never decide what to do since by that time I already have everything built up and can't be bothered to go through the massive micromanagement necessary to figure out if it's better to dismantle such-and-such cottage in favour of a watermill, etc. Is there a "quick" way to determine what to do?

[proviisori]

Re: Questions about civics, diplomacy, improvements, etc.

Originally posted by NFIH
I have several questions regarding these issues. Any help is appreciated.


2. How does the AI adopt two different civics on the same turn? I see this all the time. I thought you could only change to one at a time. But I can't seem to do it. Instead I get the message, "can't change civics for five turns."

You should select all the civics you like and after that leave the civics screen. Don't do it one at a time... that will cause you wait that 5 turns.

[Quillan]

Re: Questions about civics, diplomacy, improvements, etc.

Originally posted by NFIH
4. How do you manage your empire defence in the context of wildly unpredictable AI? For example, in my current game, I have "friendly" relations with Cyrus and we share the same religion. He has attacked me anyway. So how do you effectively defend against not only the people you know are hostile to you and could attack at any time and also "friends"? I would need a truly massive army (so that I have large forces on all fronts) to have a hope of responding adequately. And having a massive army itself doesn't appear to deter the AI from attacking, especially if that army is not right at the border with the potential AI enemy. Yes, I know about having mobile forces, but that usually isn't enough to prevent losing a city or two to an attack because, one, your units still need some travel time, and two, the AI frequently attacks on two or three fronts, not just one.

5. Is it generally better to upgrade existing units or buy new ones. Usually, I only upgrade when I need a quick emergency force to defend or I have lots of extra cash. But is this the most efficient approach?

6. When and where do you use windmills, watermills and lumbermills? I can never decide what to do since by that time I already have everything built up and can't be bothered to go through the massive micromanagement necessary to figure out if it's better to dismantle such-and-such cottage in favour of a watermill, etc. Is there a "quick" way to determine what to do?

2 was covered by the prior poster, so here's my input on 4, 5, and 6. The way I handle defense is to maintain sufficient garrisons in ALL cities to be able to stand up for a short time, as well as a mobile force to respond to an invasion. That usually is fast attacking troops plus artillery pieces for collateral damage. I try to keep enough to blunt an attack and stall them long enough for me to build the troops necessary to repel the attack completely.

Upgrading units for me is normally done in 3 cases: 1) It's an emergency, 2) The troops in question are either elites or have promotions that the troops they'll upgrade to cannot buy (like City Raider promotions on axemen that infantry cannot get), or 3) I've got loads of excess money. Otherwise I'll normally just build new ones.

I use windmills in a couple of circumstances, either I need more food production to allow the full are of the city to be worked (area is mostly hills, for example) or I'm trying to increase the commerce production of an area that's mostly hills. Watermills I use when I need a production boost in an area that's all flatland but has a river, since it doesn't reduce food production like a workshop does. They also generate extra commerce, especially after you've developed Electricity. Lumbermills I use when I need production, have forests, and want to keep them. I also use them in tundra a lot, since a tundra square that isn't adjacent to a fresh water source can't be irrigated. Tundra forest with a lumbermill is productive. Tundra without irrigation is useless.

[padillah]

Some info that generally helps in these questions is the level you play at and the map type.

If you play at a high enough level the AI will attack more readily than at lower levels.

Also, how big do you think a massive army is? I posted this question here already (look for "How big is your army") and got an amazing response. I've been short changing my army this whole time. there are builders that suggest 6-8 units per city as a start for defence. Then step that up by almost double if you are at war!

As for uprading I usually only upgrade units that have a certain amount of experience. Remember, later in the game someone (usually two or more someones) will attack you and you can get more experience from an AI enemy than a barb. Also, you get buildings and civics that add xp so it's not that impressive anymore. So, if it's a warrior with 15 xp I'll upgrade it but if it's a maceman with 4 then I won't (heck I can build that with a barracks).

With the right buildings you can build units with 10 or 12 xp to start so you have to raise your standards.

EDIT: But if you don't upgrade them don't forget to disband them if they are truely obsolete. Otherwise you are paying upkeep on a negligable unit.

(Note: take any advice I give with a grain of salt. I have yet to win the dang game)

Tom P.

[NFIH]

Originally posted by padillah
Some info that generally helps in these questions is the level you play at and the map type.

If you play at a high enough level the AI will attack more readily than at lower levels.

Also, how big do you think a massive army is? I posted this question here already (look for "How big is your army") and got an amazing response. I've been short changing my army this whole time. there are builders that suggest 6-8 units per city as a start for defence. Then step that up by almost double if you are at war!

Oh yeah, I recall that thread. I remember that the most common response was 2-3 units per city, not 6-8. Maybe I'm remembering wrong.

I go for having only a few units in cities that appear to be well enough back from any potential fighting, a large force at the frontline(s) and a mobile force (if resources allow) that is at the centre of my empire and which is used to go defend against a sudden invasion.

But all of this doesn't work that well when I can be attacked from four or five different locations because of AI's that are "pleased" with me one turn and then sending a massive stack of doom the next.

[padillah]

Yeah, it's here if you want to give it another look.

I just scanned it and I didn't get the concrete numbers I was looking for. Plenty of "small army until later when the econ can afford it" type stuff but nothing that really pinned down my problem.

I did get a general sense for how big my army needed to be and a good reminder to hit F9 every once in a while.

Tom P.

[Willem]

Originally posted by NFIH
For example, in my current game, I have "friendly" relations with Cyrus and we share the same religion. He has attacked me anyway.

If you're being attacked by a Friendly neighbour, especially Cyrus, then it probably means that you don't have a strong enough military. Any civ will attack you if they consider you to be weak. Keep an eye on your Power graph in your info screen. If you're at the bottom of the graphic, you're at risk. If you're towards the top, most civs won't even consider attacking you.

5. Is it generally better to upgrade existing units or buy new ones. Usually, I only upgrade when I need a quick emergency force to defend or I have lots of extra cash. But is this the most efficient approach?

That could be part of your problem mentioned above. If you never upgrade, your power rating will be lower than it could be. I wouldn't bother upgrading units that don't have nay promotions though, just those that have gianed at least a level or two. Build new ones to replace the obsolete units ASAP.

6. When and where do you use windmills, watermills and lumbermills? I can never decide what to do since by that time I already have everything built up and can't be bothered to go through the massive micromanagement necessary to figure out if it's better to dismantle such-and-such cottage in favour of a watermill, etc. Is there a "quick" way to determine what to do?

Look at what your city needs. If it looks like the production capacity is low, then a few watermills would be helpful. Windmills come in handy for cities that don't have very much framland but lots of Grassland Hills. As for Lumbermills, I always save the forests that are on non-river squares, even Hills. A forested Hill with a Lumbermill give the same yield as one with a Mine, but you also get a .5 health bonus for it.

[Jaybe]

re Willem's #6 response:
I will rarely replace a Town with another improvement because they are such long-term investments. Cottage is another matter.
Lumbermill has the same production as a mine, the tradeoff being 0.5 health vs. the hammers for chopping the forest. If you typically have no health problems, then if you have need of hammers from the chop, then go with the mine. OTOH, lumbermill & watermill take longer to build (especially at Marathon speed). I typically play Rome, which has health benefits, so I rarely have health problems except for my Globe Theatre city.

re unit upgrades:
If you have a low power ranking, then by all means get more power! If you have money & upgrades to do, then selectively DO them; otherwise BUILD more units unless you want to INVITE someone to declare war on you! If you don't want to be invaded at all, then see what you can do to be first on the power graph -- less fun, but no surprises.
Remember that upgraded units will be capped at 10 XP (but retain experience LEVELS & promotions). I will typically upgrade border areas while some inland central core cities may have a single archer as garrison until the end of the game (huge maps).

[Nugog]

Re: Questions about civics, diplomacy, improvements, etc.

Originally posted by NFIH
4. For example, in my current game, I have "friendly" relations with Cyrus and we share the same religion. He has attacked me anyway.

As others have already said, it sounds as though your army was too small, or not "powewrful" enough.

So a larger, stronger army is the order of the day!

And then you can send it out on a "training exercise" in your "friends" territory!

[NFIH]

Originally posted by Willem


If you're being attacked by a Friendly neighbour, especially Cyrus, then it probably means that you don't have a strong enough military. Any civ will attack you if they consider you to be weak. Keep an eye on your Power graph in your info screen. If you're at the bottom of the graphic, you're at risk. If you're towards the top, most civs won't even consider attacking you.

Sigh. I'm third out of 11 in power right now. I share the same religion as four other civs. I'm being attacked by Isabella--who is coming across two other civs (who don't share her religion) to get me. WTF? Alexander has now joined in to attack me. I can't get anyone to even consider a request to attack either Isabella or Alexander--and three of those I've asked are either friendly or pleased toward me and share my religion. Everything is redded out. Game over.

That could be part of your problem mentioned above. If you never upgrade, your power rating will be lower than it could be. I wouldn't bother upgrading units that don't have nay promotions though, just those that have gianed at least a level or two. Build new ones to replace the obsolete units ASAP.

Yeah, as I said, in the current game I'm playing power isn't an issue for me. I can hold off one stack of doom--but not two coming from opposite ends of my empire. It's so annoying.

[Blake]

Isabella tends to attack whoever she likes least. She is predictable, if she doesn't like you, she'll attack you. She wont attack her friends.

Alexander likes to pick strong targets, he wont attack his bestest friend in the whole wide world, but anyone else is fair game, he seems to especially enjoy attacking religious "allys" and peaceful civs. Alexander is unpredictable, unless you're his bested friend you're a potential target (he WILL attack his lesser friends!).
If you wield Alexander properly he is an incredibly potent weapon, if you're his best friend you can easily bribe him to attack anyone you want.

If there's one piece of advice that will help you survive, it is this:
BEFRIEND WARMONGERS.
The peacemongers like Mansa Musa will still trade with you even if they don't like you, and they wont ever attack you. Warmongers on the other hand definitely will attack you if they don't like you. So it's better to be friendly with the warmongers, get really friendly with them. Warmongers enjoy war so they can be bribed to help you or hinder others. Peacemongers on the other hand hate war, so are incredibly hard to bribe.
The warmongers are more useful as allies while the peacemongers are less dangerous as enemies. Choose your friends accordingly.

Now when you end up getting dogpiled anyway it's really not that hard to fight off the AI attacks, even multiple AI's at once. The whip and the draft are your friends, be ruthless with cities which are in danger of being lost. You'll probably find that a single round of whipping (in every city) will be enough to counter an AI SoD, if not... just keep on whipping and drafting, they'll forgive you eventually. A city which is really pissed off is more useful than one in enemy hands. Whip the less important cities right down to size 1-2 if that's what it takes. Once the AI attack has been driven off you can take the AI cities and the new happy reosurces should cover any whip anger.

[NFIH]

Originally posted by Blake
Isabella tends to attack whoever she likes least. She is predictable, if she doesn't like you, she'll attack you. She wont attack her friends.

As soon as I see Isabella in the game I put her down as a target, only slightly behind Montezuma.

Alexander likes to pick strong targets, he wont attack his bestest friend in the whole wide world, but anyone else is fair game, he seems to especially enjoy attacking religious "allys" and peaceful civs. Alexander is unpredictable, unless you're his bested friend you're a potential target (he WILL attack his lesser friends!).
If you wield Alexander properly he is an incredibly potent weapon, if you're his best friend you can easily bribe him to attack anyone you want.

And how do I determine that I'm not his "best friend" if I already have "friendly" or "pleased" relations with him?

If there's one piece of advice that will help you survive, it is this:
BEFRIEND WARMONGERS.
The peacemongers like Mansa Musa will still trade with you even if they don't like you, and they wont ever attack you.

Well, that's not true. I've been to war with everyone.

Warmongers on the other hand definitely will attack you if they don't like you. So it's better to be friendly with the warmongers, get really friendly with them. Warmongers enjoy war so they can be bribed to help you or hinder others. Peacemongers on the other hand hate war, so are incredibly hard to bribe.
The warmongers are more useful as allies while the peacemongers are less dangerous as enemies. Choose your friends accordingly.

I play with random personalities since I play against random civs, so I'm not sure who is who. But I just assume the usual suspects are the usual suspects--Monty will attack on turn 2, Isabella soon after, etc.

Now when you end up getting dogpiled anyway it's really not that hard to fight off the AI attacks, even multiple AI's at once. The whip and the draft are your friends, be ruthless with cities which are in danger of being lost. You'll probably find that a single round of whipping (in every city) will be enough to counter an AI SoD, if not... just keep on whipping and drafting, they'll forgive you eventually.

Hmm, not when I'm fighting off a stack on one end of the empire with my own stack only to get hit at the opposite end by a stack of about 10 macemen, 8 knights and several catapults as has just happened to me. Of course, I whipped and drafted, but that's just one unit per turn per city--hardly enough to fend off a SoD that is itself only one or two turns away from a given city. The city or cities will fall before the new units can even reach the targeted city(ies).

I don't even mind it except for the maddening refusal of all AIs to be bribable by me. The options are redded out 99% of the time--even if my relations are friendly or pleased. The game surely should at least give me the option of putting something on the table and then having the AI decide if it likes my offer. To not even give me the option while the AIs routinely ally with each other against me is deeply annoying. Basically, every game is me vs all the AIs on one de facto team, even though it's supposed to be a free-for-all. I also think there should be an option to demand of an AI that it break relations, etc., just like the AIs ask of me every single turn (God, that's tedious in an 11-player game.).

(An example from one of my current games: Isa came across two civs, one of which was Elizabeth, to attack me. Elizabeth was Confucian. So was I. Isa is Buddhist and borders Elizabeth, not me. Elizabeth is "pleased" with me. OK, she lets Isa through her territory. Bad enough. Then I check to see what I can do with Elizabeth. Incredibly, both the option to have her break relations with Isa and go to war with Isa are redded out. WTF? We share the same religion, we're pleased and I'm not even allowed to offer terms to get her to do something for her? How's that? Is there some secret I'm missing to at least getting the redded out crap removed? Because if I'm already bosom buddies with her, I really don't know what else I can do.)

Right now my only solution is to maintain a really massive army so that every border has a strong deterrent. But this affects my economy so it's something for which I'm still looking for a solution.

One other related question: Does an AI that is considering attacking judge not only total player strength but where on the map that strength is concentrated? For example, if I pull forces away from border A to fight on border B does the AI on border A recognize that I'm in fact locally weak?

[Six Thousand Year Old Man]

I think I lucked into the 'befriend the warmongers' approach in my current game. My nearest neighbours are Monty (on the other side of an ithsmus choke-point which I have held from day 1 and securely garrisoned) and Kublai Khan. I've been trading with them for a long time, and neither of them have ever raised a finger against me.

It may also help that I'm playing Isabella. So the evil little b*tch can't get me. And perhaps now that I'm the evil little b*tch, the other warmongers respect me more?

One tactic I have used successfully is shortening my lines of defense. If I'm invading a neighbour, I'll do my utmost to eradicate him/her totally, but if I can't, I'll at least try to halt at a point where the AI can only reach 1 or 2 cities via land (like my ithsmus situation, above).

One other related question: Does an AI that is considering attacking judge not only total player strength but where on the map that strength is concentrated? For example, if I pull forces away from border A to fight on border B does the AI on border A recognize that I'm in fact locally weak?

Based on my experience, yes.

[NFIH]

Originally posted by Six Thousand Year Old Man

One tactic I have used successfully is shortening my lines of defense. If I'm invading a neighbour, I'll do my utmost to eradicate him/her totally, but if I can't, I'll at least try to halt at a point where the AI can only reach 1 or 2 cities via land (like my ithsmus situation, above).

I try to do the same. But I'm currently playing pangea maps where there are basically no choke points. (Also, it's incredibly difficult to wipe out an enemy civ in one go before expense costs or unit losses catch up with you. You really need a very large army to do this, but if you wait to build up such a force the enemy's defences will also have become stronger, leaving you no further ahead.)

[Feyd]

Re: Questions about civics, diplomacy, improvements, etc.

Originally posted by NFIH
I have several questions regarding these issues. Any help is appreciated.

1. I notice that when I put some buildings in the queue, the hammer production goes up even if that building is not the actual item being built (e.g. it's second in line). The message is "100% hammers for collosseum by creative leader" or "100% for temple by spiritual leader." But the building isn't even built yet--it's merely in the queue. How does that work?

That is due to the new "rollover" production added into Civ 4. If you mouse over the hammer icon for the item you're producing on turn 1 you will see that up to your production is matched by "rollover" from your previous build. Therefore if you are building the colusseum and consider changing to an aqueduct you will find that the turn numbers may be different before you add it to the queue because the computer is giving you the turns to build if you put it at the top of the queue and received those rollover shields. It cannot do it for those items further down the queue because there is no rollover to change the production time for those.

Originally posted by NFIH 2. How does the AI adopt two different civics on the same turn? I see this all the time. I thought you could only change to one at a time. But I can't seem to do it. Instead I get the message, "can't change civics for five turns."

Answered by others. You can change all four categories of civics in one go. A long period of anarchy will follow (unless you're spiritual), but it WILL be shorter than changing them all separately.

Originally posted by NFIH 3. I'm not quite getting diplomacy in terms of how the AIs react to me. Specifically, I would say that about 99% of the time, I can't get an AI to go to war against someone else if I ask. This is even if I have "pleased" or "friendly" relations with them. What I don't get is, why is the option immediately redded out? I don't even have the option to offer something (cash, tech, etc.) so the AI can see whether it would be worth their while--and this is even if they're pleased or friendly toward me. In all the games I've played, I've only had the option to get someone to come on side with me maybe five times. Meanwhile, the AIs are asking me to go to war against someone pretty much every single turn (but they often don't actually declare war themselves!)--so much so that it gets quite tedious.

As others have said personalities and traits play heavily into the options you receive. If you want to look through the XML you can find the LeaderHeadInfo file to see just what this constitutes. A lot of factors play into it though. For example, even though someone may be pleased with you they may be friendly with the other AI. To check this go to the diplomacy screen and highlight the leader you don't like. You can see how the other leaders are responding to him/her there.

Alternatively, the AI could simply be considering what you have to offer. If you are sitting on zero cash, no new techs, and nothing to trade then they red it out simply because you don't have the 50 gold they might want or the luxury resource they would need to deal with the war weariness. On the flipside they consider what would happen if YOU got ticked off at them... I play a less challenging game and so I'm rarely out of the leader spot and regularly ahead in tech and so people will do what I say without compensation normally because they would rather fight a battle with somebody they don't necessarialy dislike and who is almost equal in power to them than displease me... "Hail to the King, baby!"

Finally, AIs are not as stupid as they used to be. The old strategy I used to use was to get friendly with some AI and have it declare war on another AI just to watch the fight. After awhile I could be persuaded to be brought in (for a price) and declare war on the enemy that I wanted to fight in the first place. It dented war weariness quite a bit not being the aggressor. Sadly, the AI doesn't necessarially fall for that one anymore. Elizabeth is BETWEEN you and Isabella with a horde of SoDs in her territory. What can YOU offer her in forms of protection or compensation for the beatdown she would receive just to blunt the damage to your civ?

Originally posted by NFIH 3a. There are also many situations where an AI asks you to declare war. If you say yes and ask on that same exchange for the AI to attack someone else in return, you only get the option to choose a particular city, not an entire empire. Why is that? Does it make more sense to decline the request to attack Y, then declare against Y on the next turn and then ask the AI to declare against my own target empire?

If you're talking about the "Coordinate attack" then that only deals with your mutual foe. You go through the same old diplomacy screen to get them to attack another civ (the "my column/your column" screen).

Originally posted by NFIH 4. How do you manage your empire defence in the context of wildly unpredictable AI? For example, in my current game, I have "friendly" relations with Cyrus and we share the same religion. He has attacked me anyway. So how do you effectively defend against not only the people you know are hostile to you and could attack at any time and also "friends"? I would need a truly massive army (so that I have large forces on all fronts) to have a hope of responding adequately. And having a massive army itself doesn't appear to deter the AI from attacking, especially if that army is not right at the border with the potential AI enemy. Yes, I know about having mobile forces, but that usually isn't enough to prevent losing a city or two to an attack because, one, your units still need some travel time, and two, the AI frequently attacks on two or three fronts, not just one.

Remember, the AIs talk amongst themselves much better in this version of CIV than previous ones. Likely Cyrus was given cash and other considerations by Isabella whom he saw as the winning horse anyway. Treachery is something I see as a great part of the new system. Basically what I do for defense is drop 2-3 units in my cities that could be reached within a turn or two of a declaration of war. Two units if they are at least City Defense II, three if not. I also build walls and castles. With culture (which in my border cities is a priority) defense these three units can normally hold out vs. a big stack long enough for my mobile defense to show up on my massive road network.

Mobile defenders are very important. I normally keep five calvary units and a good collection of axemen/macemen/riflemen/infantry at or near my borders. Regularly they are fortified on a lumbermill hill near my most important border city. What makes up these defenders? Well, basically it's one or two stacks of doom that would comprise my attack force if I were the one declaring war. Regularly they are highly trained troops with combined defensive bonuses (one guerilla II, one Woodsman II, and one medic plus five to seven other 2nd level or higher of my best tech units). I do try to keep one at each border where the AI is a threat. If I've turned one AI into a "redheaded stepchild" by cutting them off from the world then I will neglect that border, but otherwise no even if they are friendly.

Finally, since I have three defenders at each of my border cities I can afford to lose one to reinforce the city they are attacking. I might have to take the long way around, but normally I can move them in to reinforce and the AI is none the wiser that my other cities are a little weaker. Honestly though? The AI may be a little smarter, but they are still dumb when attacking... they still only threaten one city normally when they drop their stacks of doom...

Originally posted by NFIH 5. Is it generally better to upgrade existing units or buy new ones. Usually, I only upgrade when I need a quick emergency force to defend or I have lots of extra cash. But is this the most efficient approach?

I always upgrade everything just for the sake of uniformity. This is normally because I play generally peaceful games, but I also regularly take the time to drop science production to build upgrade cash once I get Rifiling in order to change all of my old melee and archery units into riflemen.

If I hadn't upgraded though? I would always try to keep enough cash on hand to upgrade a handfull of units anyway. Your border defenders should always be your highest tech defenders!, but I sometimes will move a lower unit in from the interior and upgrade it if it is needed (i.e. he sends "scouts" or "raiders" past the city he is attacking).

Originally posted by NFIH 6. When and where do you use windmills, watermills and lumbermills? I can never decide what to do since by that time I already have everything built up and can't be bothered to go through the massive micromanagement necessary to figure out if it's better to dismantle such-and-such cottage in favour of a watermill, etc. Is there a "quick" way to determine what to do?

Heh... you've got me boss. I like building watermills, but it never seems like the AI is recommending them. It just depends on what I'm doing with the city. I'm trying to work on my specialization skills and so in some cities I will farm everything and drop windmills on every hill. High food=more specialists=more GPs. In others I will focus on commerce and so I spam cottages and windmills. In production cities it's mines and watermills.

As for lumbermills... I normally last to the endgame (i.e. lumbermills) with 2-4 grassland forests per city just for the health benefits. Once I start building up a health bonus through improvements, resources, and trading, I will normally drop to two per city. Grassland forests are the only ones worth keeping imho and so irrigate your plains and keep some of your grasslands forested. That said... if you have a forest you have a lumbermill and eventually railroad. In the end if your city is never going to reach it's health cap (you can tell after biology) I would say to clear cut the remaining forests for the production boost.

Oh... and unless you have to keep it to have your 2-4 forests per city never keep a forest on a river. Cities, lumbermills, even farms are better on a river since they get the commerce bonus. (Now if you're not planning on building a cottage or farm there keep any river grassland forests until you get watermills because that is what you will want to replace them with).

In the end it is a personal choice. If you're not specializing here's what I would do...

Food: Calculate enough food post biology to work all of the worthwhile squares (no tundra, no desert) and plan on farming enough food to reach that goal in addition to these and in place of these if necessary.
Plains Hills: Windmill
Grasslands Hills: Mine
Plains River: Farm
Grasslands River: Watermill on one side/Cottage on the other
Floodplains: Cottage (you invariably work these first in a city due to the high food content. Therefore they have the fastest cottage growth)
Forests (up to 4 not on the river): Lumbermill
Forests (on the river): keep until replaceable parts and then Watermill

Once a cottage gets to a village I will very rarely pave it over, but if I do it will be pillaged instead of built over. If I am playing a financial civ I'm normally more cottage heavy and will forgoe farms and watermills on grasslands.

Well, hope this is enlightening. Cheers...