It depends, I don't like to backstab my allies for no reason, so if all my neighbours are friendly, I'll sit tight and develop my provinces. Maybe that's because I play GA, but sooner or later someone's gonna attack you anyway, and then it's on. My last campaign (Danes, GA) I actually did nothing for the last 50+ years, just so I could see what happened when the game ended with me having the most points. Not to exciting.

Bottom line: I usually play slow, but conquer in bursts, when someone violates my territory.