Txurce
Deity
1) For each playstyle, in general, what are you doing for the first 100 turns? What are your primary goals? Which leaders do you prefer? Techs, Wonders, Diplomacy, Scouting, etc.? Navy or land based units? Are you ignoring happiness and selling all of your luxury items ASAP? Are you rushing a close neighbor as early as possible? Are you beelining to bronze working to see where the iron is before putting down your second city? Also, what policies do you emphasize? How important are CS's this early? Maritime vs Cultural vs Militaristic.
I choose the Victory Condition before I start; many others don't. I choose leaders accordingly. Thal likes the Mongols for war; I find Germany irresistible. Culture leans toward Siam, India, France, Songhai and the Aztecs. Babylon and Korea are built for science, but lately I've written about better results by expanding quickly with early culture-rich civs like Songhai and France; civs with high pop potential like America and Siam, specialists like the Ottomans, gold like Arabia, and GA's like Persia are also good for it.
Neighbors theoretically determine a Tradition vs Liberty choice, but I base it more on civ. I try to check for iron early, but delay it if my focus will be on something other than swords - and it usually is. I always start Scout, Worker, Monument, GW (some combination of GL/Pyr/HG), then go either the NC or expansion route. Neighbors have everything to do with this. I've learned that attacking even a protected settler, even prior to having any sort of army, is always worth it: a big plus for you, big minus for him, and an almost guaranteed eventual favorable peace treaty. (Just be ready to rush an archer!).
CS are situational. All are helpful. Friending a Militaristic one for the rest of the game can give you an ample, up-to-date defensive army at negligible cost. But I tend to save my gold for RA's and rushing certain buildings (I love Water Mills while building my first GW).
2) Mid to late game, what are you emphasizing? What buildings do you build or buy in your new cities to accomplish this? What are your policy choices now that you have gotten the early choices out of the way? How do you use specialists - this is the biggest one for me, as until lately, I haven't messed with them a lot. One thing I have never done much of is conquering a city and then selling it - is that a huge leak?
I always have monuments, libraries and colosseums. I try to get to temples asap, but often delay for something else. Later buildings are based on goal. For science, I aim for universities on up, along with pop enhancers, and squeeze in production boosters once I can wait for something. The GW's that draw me (and tend to be available) are PT, SC and BB on occasion (they're popular) in the mid-game, after which I beeline for SoL.
Policy in a science game follows either Liberty or Tradition with almost definite Patronage to get either the first two (universal influence boost) or all of them depending on my culture generation. (The Patronage happiness boost is key for expansionist science wins, and now also helpful for boosting science in tall civs.) I used to go for the GM in Commerce, and would still do that if universal CS influence won't do me much good because I'm not generating a lot of gold. Then I go to Enlightenment, fill it out except for the last policy, and move on to Order, if possible.
I start using science specialists as soon as a city hits 6, and add a second at 9. I try to build a GE, but often don't get around to it. The occasional GM is always a welcome gold boost, but again, I tend to focus on science. I ignore artist specialists except in culture-victory games, until I manipulate the arrival of the last Enlightenment policy.