The only two things that worked for me were therapy to learn how to notice when I felt the urge to pick and to figure out other things to do instead and getting on an anti-anxiety med. For me, it wasn't a habit, it was/is a compulsion. There's a part of me that absolutely needs to pick at my skin...it's a pressing, overwhelming need. Someone telling me to stop does nothing for me except upset me. If I could stop that easily, I would have done so years ago. It took a lot of work getting my anxiety under control to see even a small drop in the skin picking behaviors. It took going on medication for anxiety to really make a huge impact.