Decide you are sure that you wish to quit biting nails, and stick with it. It is next to impossible to quit doing something if you want to keep doing it. By deciding to quit nail biting, you admit that a problem exists, and you want to get rid of it.
Reduce the number of situations that make you feel like biting your nails. Studies have shown that most people bite their nails when they are under stress, anxious, bored, hungry, and they occasionally do it without noticing. Identify when you feel tempted to nibble, and avoid the situation(s) as often as possible. Having limited the situations of your bad habit , you will think about it less frequently and thus lower the temptation to chomp down.
Avoid putting your hands near your mouth at all times. Not only will you avoid exposing your mouth to copious amounts of microbes and bacteria ( think about all the doorknobs you turned, tables you touched, and handshakes you gave), but you also are physically incapable of biting your nails without putting your hands near your mouth. Idling hands near your mouth is a bad habit in itself because there is always a chance of contracting an intestinal parasite when you put your fingers in your mouth.
Another critical step is a fairly common one, especially for those who are trying to quit smoking. Distract yourself with another activity whenever the temptation is strong. Occupying your hands with a task will greatly benefit your effort to quit nail biting because it sets your mind on other tasks. This inevitably makes you...