Quote Originally Posted by WhiteShark
what i do is : I invade enemy city on my border, sack it but DO NOT destroy buildings.

Next step is to purposly make public order so that Independent(Rebel) forces will overrun the settlement. That way, it makes a natural settlement and because of the strong rebel army from indestroyed barracks, enemy will have a hard time recapturing the city.
That's something I also do, particually to Rome, which often grows to fast, as it has it to easy most of the time.