For some reason and for some people, nail biting is soothing in the face of stress or worry. If this sounds familiar to you, it may help to use relaxation or stress reduction techniques to overcome the urge to bite. These therapies can be very effective at reducing stress and anxiety, which is probably at the root of the biting problem.
Relaxation may also come through the creation of a soothing environment, such as drinking herbal tea and using lotions that have soothing scents. According to Tanya Clausen, clinical social worker in Washington, D.C, certain breathing techniques, such as deep breathing or quick breathing may reduce the stress or anxiety that may cause you to want to make a meal of your manicure.
Nail biting may also be accompanied by other body-oriented obsessions such as hair twirling or skin picking [source: WebMD]. All of these can have a negative effect on your appearance, which is often the main reason people want to stop the behavior. With that in mind, consider that one of the most effective methods of breaking the nail biting habit is simply being able to envision victory over the problem.