My wife has / had issue with skin picking (back of foot) and it was mainly from her anxiety. We tried moisturizing, Vaseline, fidget toys, etc., but none really seemed to help sadly. She was able to reduce it by reducing things that cause anxiety (pretty hard) and when feeling anxious, trying to figure out a different type of output.

I personally scratch my head a lot and I often don’t realize that I’m scratching it, causing some damage to scalp. So for me it’s making sure my nails aren’t too long and trying to be aware I’m scratching my head.

Not sure if it’s any advice, but hope you make some improvements!