How to play as turtle..

[Smith_X]

I wondering about how do I turtle..

If I want to upgrade my tech very fast with quick expand and start research like...

1. Science
2. Civil --> start build base 2, gather timber and food
3. Commerce
4. Civil --> start build base 3,
5. Commerce or Classical Age

what's the best way to defend my base ?
1. halt some research and start research military and build turret.
2. build fort ?

oh I forget this is my plan for play with Medium AI 1 on 1.

Last game I got blow with lots nuclear that I cannot counter my opponent and lost at the end.

I need to improve my strategy.
moreover, at last game.. I do not know I can send archer to garrison in tower and that will make my tower stronger..

but are there anyway to stop enemy siege unit ? or just have to use cavalry to counter it only ?

[Q Classic]

on medium, which i win about half of the time so far (bloodily, yes, but) i usually go

science and civil right off the bat, then build lots and lots of settlers, funnelling everything i can into research.

i build two barracks or so and one stable, and pump out a small force for defense.

at the end game, i usually then build a massive force.