Notice it. Interrupt it. Practice again.
Habit reversal training (HRT) helps you recognize early signs and use a competing response that makes biting, picking, or pulling harder to do. We also change the situations that cue the behavior and build practice into real life.
For nail biting, that might mean noticing when a finger starts moving toward your mouth, using a brief hands-down response, and planning for high-risk moments like screen time or driving. The response is tailored to you.