Generally speaking I tend twards having three families on separate save files so that I can play my sims the way i want to without any impact on the others
Though once I finish up everything that I want to do with a household I'll have the characters be a part of another characters world.
I tend to control most everything that my sims do because I have ideas as far as what kind of characters I want them to be so it's easiest to have about four sims per household at most so that I can get them all where I want them to be efficiently before sending them off to do other things on their own.
