I play rotationally and I like playing all kind of families and trying to make my households different form each other. Still I often end up with mum, dad and two children. The variation is having one or three children... I try to play bad sims too, but the game makes it hard because sims are autonomously so nice to each other. I think with bad characters it's important to remember that they aren't completely bad. They have a soft spot too and then they have something that drives them to be bad, justifies their behaviour.
What I enjoy most in my game is when I start with one household, then play their club friend, then a brother, then their enemy, it just continues and the sims are some how linked to each other. I often have some kind of loose storyline in mind, but leave room for new ideas. I tend to think what each sim child wants to become when they grow up and then aim for that. However I love surprises that the game throws at me and change my plans accordingly.
I don't know if this was any helpful though since you mentioned you don't want to switch constantly... Not sure what is constantly to you though. I'm thinking you could concentrate on one family pretty long before switching to the other, as long as they keep aging about the same pace. I really love rotational play, so I'd warmly recommend giving it a chance 🙂
