Bottlecaps can help with skinpicking/dermatillomania!
Carry a few in your pocket at all times. When you feel the urge to pick, pull one out and start picking at the vinyl liner inside the cap. It has the same sort of tactile feeling to your fingers as skinpicking, and when you manage to remove the liner from the cap, you have the same feeling of satisfaction or weird accomplishment—but no holes in your skin, torn nails, picked scabs, etc.
You can buy a bazillion of them at a time from places like Etsy or eBay. Make sure they have the vinyl liners in them—craft supply places tend to sell them without.
I’ve suffered from compulsive skinpicking/dermatillomania literally since I was born. It’s a constant battle. I’ve followed all sorts of advice, from “draw patterns on your skin with your fingertips instead!” to the ever-unhelpful “mind over matter!” but the bottlecaps have been the only thing to reallyhelp me a lot.