I tend to play legacies (though I admit I hardly get far in them) so if I’m playing just for fun, I always create the next generation’s spouse with traits that play off their aspiration and/or career choice. So if I’m creating a spouse for them that has one of the mischief aspirations then I’ll use those more negative traits like evil, hates children, etc. Hates Children is probably the one I’d say I use the least and that’s just because, as I said, I play legacies and I can’t bring myself to make a person that hates kids have kids and/or to have a kid whose parent hates them. But I will use it if it fits the sim.
If I’m playing a challenge that requires the spouse to have certain traits then I just find the first townie that I like the looks of that has that trait, I don’t pay too much mind to whatever other traits they have. If I am gonna have my sim marry a townie, as shallow as it sounds, their looks are more important than their traits just because sometimes sims genetics don’t turn out well at all, even if both parents are whatever I would define as “attractive”. I try to give my next generation the best shot that I can lol.
As for the spares/other kids that do not end up being the heir for the next generation, I leave that up to fate. I typically end up hooking them up with whoever their first friend is from school or the first one I see them hang out with multiple times. I don’t micromanage their traits or anything, the only thing I might adjust is their outfits but only if the game gives them something ridiculously random. Otherwise I leave them as they are. If they have the hates children trait, I just typically don’t have them have kids. Otherwise I might pop in and give them a kid or two before going back to my next generation, just to give some more life to the town/game.
