so my younger sister has a terrible problem with biting her nails. whenever i try to pain them, they are short, and messy. here are some quick ways to stop biting your nails.
+ you have to want it. if you don't really care, this won't work. you have to try and image how pretty a perfectly manicure set of nails will look.
+ set a time goal; give yourself a goal. i will stop biting my nails for two weeks. maybe, after two or so weeks, go get a professional manicure. this gets you into the habit, and also makes you want to stop.
+ clear nail polish; if you aren't wearing a color nail polish, always wear a coat of clear. that way, you purposely try not to ruin the shine of your nails, and the nail polish can sometimes taste yucky in your mouth.
+ have your friend/family help you; when you are at school, ask your closest friends to watch you, and every time you bite your nails, have them tell you, or stop you. at home, do the same thing. i had to help one of my friends stop and it took her about a month, but now she doesn't bite her nails at all.
+ relieve stress; you may bite your nails because you are nervous. is you are scared or worried about something happening soon, try to talk it out. get all the worriness out of your system. it helps you be more confident.
hope this helps,