Mostly Generational - but a lot of the time I just create spouses for my Sims so as to skip the slightly sordid business of chasing down townies who are too old/young because you've reached the point it's them or die alone. Also your kids get to look the way you want 'em, which is a biggie.
Apart from this, my focus in game is levelling stuff up - school grades, careers, skills, upgrading appliances. The house gets chopped around a lot but I never move lots, and it tends to look rather rough but be ergonomically effective.
I'm not one for making family dramas. I never divorce my Sims, have never had them cheat on or be mean to each other, and try to keep them alive as long as possible. I try to keep the all the needs as close to full as i can, and work on fixing uncomfortable moodlets ASAP.