I also like the idea of having some things be random, or choosing between limited options that are randomly generated. Here's what I'm doing these days. The random rolling allows sims to be more individual and I end up using more diverse traits and aspirations than I would choose on my own. I like that they surprise me.
When it's time to choose traits, I roll 3 choices. If a trait appeared that's shared by both parents, I choose that one. Otherwise, if a trait appeared that one parent has, I choose that one. If no parental traits appeared I choose one of the 3 choices that I just like for that character the most, but I still roll 3 additional times to give a parental trait a chance to show up. So some of the time they inherit a parent's trait, and some of the time they show us that they are their own people no matter what the parents try to do ;)
Toddler trait is just randomly rolled once.
Aspirations- I roll 3 choices and choose the one that I like for that character the most. (I tend not to switch aspirations until completing one-- in my gameplay, aspirations aren't about collecting aspiration points since I usually end up with way more than I need regardless, aspirations are about giving a sim's life some direction.)
Gender- when a sim ages up to child I roll a number from 1-100 for gender identity. 1-95 is cisgender, 96-98 trans, 99 anatomical/chromosomal intersex condition, 100 non-binary.
Sexual orientation- when a sim ages up to teen I roll a number from 1-100 for sexual orientation. 1-75 is straight, 76-90 is bisexual/pansexual, 91-100 is homosexual. Sometimes I also roll gender identity and sexual orientation for NPC sims a child has grown up with, but not often.
Oh, and for reward traits, I limit myself to one when they age up to young adult and one when they age up to adult, based on what's happened in their life experience so far. All Elders get the Observant trait.
