The first thing that must be done to quit this habit is to increase awareness of your behaviour
. Nail biting is done on an impulse. It takes less than half a second to change that impulse into an action. You need to have an understanding of your actions. This is essential to attain control over yourself. Without control, it is not possible to abstain from nail biting.
When you acquire awareness and ultimately control, you will find it easier to think consciously about the disadvantages of your habit and you will easily make the firm decision to quit. It acts like a pause button. You pause for a moment, glance at your bitten nails and find that it is better to quit!
The best way to obtain awareness over your behaviour is getting someone to help you. Tell a friend about your pledge to stop nail biting and ask him/her to remind you not to do it every time you show signs of attempting it. You might not feel comfortable with this but it is the quickest way to help you!
Who should you single out as the person with whom you want to share your problem? The person who spends the most time with you. He/she can stop you if he/she sees any suspicious movement on your part.
Choose someone who is prepared to keep the whole matter private. You do not want someone stopping you from nail biting in front of everyone. This will cause pressure and will increase your habit as you will be inclined to continue your nail biting session in a private place.
After selecting someone who is perfect for the job, agree upon a reminder. A shake of the head, a reminding cough, a simple sentence, whatever you find suitable.
In a matter of days, your nails will grow, your body will get used to avoiding nail biting and you will not need a partner anymore. Till then your friend will help you and it may be irksome sometimes but in the end you will be glad you took him/her up for the job!