You can do a lot of things! A road trip, a day off work, treating yourself to a manicure or pedicure or new clothes, jewelry, or redecorating your bedroom.
Personally, I told myself if I didn't cut on my wrist for six months, I would get a tattoo there because I'd always wanted one. And I also said I had to work on not cutting anywhere else as well (but I said the wrist first because it's where I do it when I'm suicidal) but I would not make myself stop cold turkey for the tattoo. That way, if I cut on my thighs or something, I wouldn't feel like a total failure, and I could reward myself for alleviating one part of the problem. And I REALLY wanted a tattoo, so it worked. I went actually closer to 9 months before I did it, and now I've got a tattoo right over my scars that says "tempus aurum" (time is gold in Latin) with a semicolon under it. (Look up the semicolon project for suicide awareness; that's why I did it.) It is actually a good reminder to me, both when I want to cut there and when I'm just down. I don't know how you feel about a tattoo, but that's what helped me.
Congrats on your progress! Definitely reward yourself somehow. You deserve it.
"Scar tissue has no character. It doesn't show age or illness or pallor or tan. It has no pores, no hair, no wrinkles. It's like a slipcover. It shields and disguises what's beneath. That's why we grow it; we have something to hide."
Dx: Bipolar, type II
Rx: Lamictal, 100 mg; Lithium, 1350 mg