thats right beetle, there are exceptions for every rule!
the way I pick ideological policies usualy allows me to control more and more cities, almost always through conquest, puppet, annex. With order or auto, I usualy end up with 8-12 cities by the end.
My favorite strategy is to get the city through a peace deal, and that way its got more stuff in it because I didnt have to take it by force. No matter what I do with that city, its now worth more than one I half destroyed in conquest.
I will *always* be looking to liberate one city for each one I keep. Not always possible of course.
CS are best, automatic allies.
Recalling dead AI is second best, because they will probably love you, instant DoF for you, Denouncement for whomever killed them off. This can help win Diplo victories, as recalled players are way more likely to vote for you.
last : I love selling cities to other AI to create more border tensions. I love to puppeteer the AI into wars with each other, and profit all the while. Capture city from Y, Sell it to X, wait for war...Ask X or Y for gold so I will DoW the other one...profit, repeat... win.