I have treated myself to some things. I got a nice designer purse I wanted for instance.
But mostly, I focus on self care. When I was drinking, I was ALWAYS rushing around (I had a full time day job and my own business). I felt like the busiest person on the planet. Must be fast, and efficient! I was always neglecting myself in order to get things done...rushing, rushing (though I still managed to drink heavily through all that). Priorities!!! Hungry...zip through the drive through and get crap $1 menu stuff. Bathroom...soon as I get home, no prob. Headache...deal with it. Personal care (haircuts, etc)....phsshh what? No time.
In the beginning of sobriety I consciously forced myself to slow down and consider my mental/physical comfort first. To sit and enjoy a nice meal with quality food and even try new things! I rarely eat fast food now, before it was all I ate (if I ate at all). Take the 5 minutes to visit the ladies room before rushing around on another errand. If it is going to be rainy or cold I make the effort to bring the appropriate clothing to ensure my comfort, etc.
I was on vacation with my husband recently and he caught me slipping into my old "efficient" ways. He asked if I wanted my jacket out of the suitcase because it was getting cool. I said "I'm fine" because I didn't want to trouble him to dig it out. He said "It will just take a minute. There's no reason to be uncomfortable" No, there sure isn't. He totally called ******** on me and I let him get my jacket out LOL. It's a work in progress I guess, a lifetime habit to break.
So, I don't know if you would consider those 'rewards' or not but they sure do help add constant little reminders of a positive benefit of sobriety. Most of them don't cost a dime either.