If I have to sit in one place for too long, I can't stop my leg from bouncing. I also enjoy cracking my fingers by twisting them in every possible direction, one at a time, until every joint is limber. I can even do it one-handed. My biggest indulgence is biting my lips. Many times I've chewed up a raw spot, and on some occasions, they've bled a bit, but I still consider it to be a benefit somehow.
I noticed recently that I may have some stims related to smoking cigarettes. I roll my own, and I have a very specific ritual for doing so (kind of like how I eat pancakes and french toast, haha I just remembered this weird ritual I developed once for eating french toast, I would cut each bite the same way each time, every piece was assymetrical except for the last two which were the middle pieces and in fact it was so complex that I distinctly remember forgetting how to do it after some length of time, tho I still eat them in roughly the same way) So anyways, I roll cigs like that, too, with great focus on detail and perfection. They are fun to play with, b/c they don't break or rip. Hand-crafted cigarettes are also a semi-hobby of mine, so I have to stop my jabber here.
I like anything that accepts my full attention.