I have a few different saves, one specifically for my supernaturals, a legacy one and a couple of other random ones.
But my favourite one I am so connected with most of my sims. Started as a strict rotation fully planned out. But I found this a bit hard to maintain and I used to lose interest if I got to a household where I wasn't quite sure of a plan for them, or it was a bit boring getting them there.
So then I decided I would make it more relaxed. I choose at random, but I do have a notebook of ages and family links so that I make sure they are aged up in the right order etc.
And I go with the flow more, I recently found a household with a toddler and a baby in it, no parents so I had one of my sims take them in. Took a lot of figuring out and has completely thrown off my originals plans for them, but seems to have opened up the possibilities a bit more. I also think this could go so well with Growing Together, not too sure if the family dynamics will be relevant though as they aren't official children. :/
In this save I have:
A scientist girl who took in her little alien brother (who was a massive curveball in my game anyway) when her mum died and dad moved to the retirement home. Actually ended up working so well for her story.
A pro at flower arranging and has her own store she runs with her husband and has his son and adoptive daughter chat with the customers when they get back to school.
A 5 star celeb.
A wannabe criminal who married a guy, stole his money, slept around with other men and woman fathered twins who have disappeared (literally, they have pictures in his family tree but are completely gone from game and not aging either,) but he has semi learnt the error of his ways. He got a young girl pregnant and decided he didn't want to lose this child too so they are settling down together.
I had the 'perfect' nuclear family, the son has grown up wanting the same thing, they won the lottery, had twins themselves and now his wife isn't happy.. Not sure on where this one is going to go just yet...
I have a police man. An explorer...
I need to start planning the next generations starting points really.
Basically trying to get a bit of variety throughout the families in this save. Sorry for the rambling! :D