play rotationally
stick to one family only for as long you are not bored, if bored move to another or set a new into the neighborhood
if you find some family too boring to even play them once in a while set them out of the neighborhood for good & replace with some other sims
also try to make the families as different as possible, single sims, loners, traditional families with kids, business sims, computer nerds ...
don't stay only on the home lot, this makes it very boring, go out with your sims & do something else with them than you do with the other families, try not to repeat the same life set up for the different families
also don't play with aging on, age them up on your terms, first if you think that they should move to the next age state
have more control over the sims you're playing, don't be driven by the game, play the sims with free will on & direct them if the sims don't take you where you want to go with that particular family
try to develop a connection with the family you're playing, so you know what their life is about
& if you have GT, play clubs as the main free time activity, make different clubs for different sims
dancing & night clubs are a good additional thing for your sims to do something
i would also recommend
GTW for all sorts of shops & if you want to have sims buy something in person instead to just stay home, which makes it usually very boring
Dine Out GP for restaurants to visit with your sims
Movie Hangout SP to make movie theaters & meet with some of the clubs there
Spa Day GP gives you also some more to do with your sims on a daily basis
i own more packs than those but those mainly add somewhat decent gameplay to the daily life of sims