My playstyle is a single household with aging off for most of the time, then switch to my favorite premades just to ensure they develop as I want and don't "die out". When I am emotionally ready, I turn aging on and have my household having kids then pause aging again when the kids are YA.
I even go so far as to abandon the elders, either by moving out, or kicking them out if i like the present house. I really dislike juggling more than three sims in a household.