Sorry for the novel. TL;DR started cutting pretty young, now cut my stomach with razors.
I started cutting at 11 years old. I came home from school one day and just felt so angry and sick of everything (I was relentlessly bullied throughout school). I grabbed a decorative porcelain plate on my nightstand, smashed it on the floor, and without thinking, I picked up the sharpest piece and slashed my wrist open. There was so much blood. I waited, thinking that I would die (foolish little girl I was), but eventually the bleeding stopped, I cleaned it and bandaged it and told everyone I had a nasty cat scratch there (we had about 5 cats at the time).
It felt good, so I started doing it more frequently. Whenever I had a bad day in school (which was often), I would take one of the porcelain pieces and sliced my forearm with it. I started wearing long sleeves. I was cutting on and off until I was 18, when I finally decided to get "clean."
Then my grandma was dying and I had a huge fight with my aunt, who had this weird rivalry thing with me due to her only being less than a year younger than my dad. I locked myself in the bathroom and sliced all over my thighs. I could hardly walk after that.
After that, I was "clean" until 2017, when I lost my job and a lot of what's left of my self-esteem. I now cut on my stomach, the part between my belly button and my pelvis. The thing is, I've gotten good at it. I know the places that will yield the most blood without being life threatening and how to cut cleanly so it'll heal quickly. I also disinfect my blades and wounds immediately to avoid infection.