be conscious of your actions. I know it's hard, but perhaps rub instead of pull. I find that reasonably appeases me. Instead of biting my nails, I clean under them with my teeth. Sure, gross, but better than biting/pulling/picking. I pick at my lip skin. So I started roughly running my teeth over them. Which satisfies the need for me to pick, but leaves the skin.

Also, I bought a clarisonic brush.