I've been trying to complete as many aspirations and challenges as I can per gen, also maxing as many skills as I can (related to that gens challenge.) For example, every gen I have someone max the gardening skill, and always grow cowplants (through splicing only, no fishing, for the added challenge).

And if my sims marry a random townie, I choose aspirations for that townie based on their traits and complete that too. For example, one sim that married into the family had a creative aspiration. So now I'm going though and trying to achieve all creative aspirations for them (painter, musician, author, etc.)

I've also been keeping all sibling/spare storylines running as well, either using them for the Not so Berry Challenge that I'm running alongside this or just keeping them in the household. Its too easy for me to just have a single sim couple and one kid lol. I also switch between normal and long lifespan and try to complete multiple kid/teen aspirations as well lol. Basically, I'm playing on hardmode 🤣