What's the easiest way or place to create my own designs?

I like trying to add my own stuff to the game, like pictures of shows, movies, books, whatever I think I would like in real life. I know about using Curseforge and a few other places for custom content. I want to do my own, and I was wondering what other people have had success with here when they do this too. I also would like to give my Sims some of the recipes/foods that I've made in real life, but I have no idea how to really do that.