Skin picker here. I mess around with the skin on my thumbs mostly. Scratch scratch.. I bought a 10€ fidget ring on Amazon (here) for my thumb. It's a "spinner ring" : the inner band spins. Now I just flick that ring with my index finger, flick, flick, flick. My skin is becoming softer again :) I've got the basic black silver one but you have them in every style and colour..