I don't use spreadsheets at all or have any particular order. I just play whoever, doing whatever, whenever. I have more than 300 Sims but I remember them all, because I'm obsessed with my Sims, lol.
1) how many days do you play each household? - I don't have a certain amount of days set, but I am thinking about changing that to be more consistent.
There is absolutely no consistency. Sometimes I play one for a few minutes; sometimes I play one for a few weeks. Sometimes I return to them again after a couple of days, and sometimes I don't come back to them for a year. It's just whatever seems fun to me right then.
2) What is the best time to switch between household - do you change it based on your sim's work hours, so their performance doesn't drop?
This is probably the only thing I do try to be consistent with. I hate coming into a household where all the members are late for work or school, so I try to switch right after 2am. I switch after 2 because when I switch before 2, it might be a holiday, and then the new household would have no time to keep the holiday from being terrible for them. But I'm not always consistent with this either. I might get too tired to wait until 2am to shut off the game, and then not feel like playing that household anymore.
I play with all aging off. I have lots of personal rules for particular Sims. For example, I've decided that my ghost mannequin Sim can't be seen by other Sims (except for two), so I don't let him socialize. Then I have other Sims who are extremely polite and will introduce themselves to everybody, even the weirdest townies.
