Personally: Hiking, biking, photography, DnD, and fixing things.
It sounds like a lot (because it is lol) but with ADHD having a group of hobbies I can orbit around (especially if they can overlap (like these ones))can help me avoid diving into too many new hobbies.
I make music, primarily, but i also bounce a lot. I really love writing, which comes easier than music tho i do it less. Past that hiking is like an “as often as possible or my mind will break” thing. Even our tiny local park is nice for this purpose, but i try to get around as much as im able. I like corrupting the advertisements i get in the mail with sharpies and make them look more blinging. And satanic. Or perverted.