Pick one where you have a friend who knows it well, and can help you through the pitfalls. Then build something complicated enough that you aren't entirely sure

Pick one where you have a friend who knows it well, and can help you through the pitfalls. Then build something complicated enough that you aren't entirely sure how to do it yet. "Mastery", "until I know it all", "find which ones I [like]" all kinda fit into this process, so you end up doing them all at once.