Habit-reversal (developing a competing habit) and Acceptance (a method of managing uncomfortable emotions) look to be the best bet for psychological treatment of Body Focused Repetitive Behaviors (BFRBs) such as trichotillomania (pulling hairs) and excoriation (picking at skin).
While rates of these disorders are relatively high (2%-5% of population), they are also relatively unresearched until lately.
Intersectional Life Counseling and Psychology, LLC 