I have been trying to use Zebru's mod tool but I can only find some tutorials for V2 and I have v3 which looks way different than the tutorials of v2 LOL But if you want to download the tool and poke around it yourself, maybe you can figure it out? Just look up Zebru's mod constructer. I still haven't figured it out yet, but Zebru has a brief tutorial on making a trait for it.
I have made two custom aspirations. Firstly, itâ€™s a lot of work. I used sims 4 studio to make the aspirations. It requires finding all the files for an aspiration already available in game, duplicating those files and editing them for your aspiration. You need to know how to use Sims 4 studio and everything that needs to be replaced. The first aspiration I made took me hours as I had no guide and had to work out for myself what to do. I