i say expand till there's no more room. if you can, build most cities next to rivers. go for a river spot before a non-river spot. after getting in a republic, set science to 0%, disband most of military, put happiness on 10% if necessary. then build marketplaces and banks if you can yet. buy techs for gpt, the ai is less likely to attack you. kissing the ai's butt won't work forever, but it will work long enough to get marketplaces and banks so you can afford to build a big military. after you do this, you have to make a decision whether to keep buying or start researching yourself. the farther behind you are, the easier it is to research, but only a little cheaper to buy. if the other civs are in the middle of the industrial age, i'd research myself, but if they just got there, keep buying (you can tell where they are by the cultural advisor telling you what wonders they're building, the ai almost always imediatly starts building a wonder when they can). when i get replceable parts, i take over a neighbor with artillery and guerillas. if you have rubber, great, build infantry. i suggest on emperor a stack of 30 artillery and 20 guerillas. after that, hopefully nobody built the spaceship or won the UN vote, go for domination, conquest, or if you have the resources or are a candidate, go for UN or spaceship.
tip on UN vote if not a candidate: you need to make the vote tied, then they don't vote again until about 15 turns. if an ai ever rop rapes you or ruins their rep in some way, remember it, and vote for them to help make it tied. if there are an odd # of civs, abstain.
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