I'm playing elves mostly these days, and I seem to often end up on a continent with only one other civ. I use cottage spam+forest to push Pact, smash/pillage whoever else is there with the stooges mixed with archers of leaves/hunters/the odd warrior, and then settle into happy terraforming mode and push caste system to lock up the whole continent under my culture (I'm debating whether I prefer Thessa's arcane prowess, faster promotions for your terraformers, quick granaries, effective free farm from bonus health, and free healthcare civics to Amelanchier's superior combat skills... I'm leaning towards the latter for effectiveness, since it's the getting a continent to yourself part which is the vulnerable stage of the plan and I probably won't have Mages by the time the battle is over if it goes well, but I keep returning to Thessa). The elves are the first group with which I have ever received the top ranking in any civ game (I like Sid's games, but I'm usually pretty bad at them), and I'm giving them a lot of attention on account.