Or an answer you can try for yourself...How about avoidance is the best practice. If you just stay away from those ppl, and get into a group of friends where everyone is cool to hang or just chill about things then do so. Dont try and be a hero in anyway, there are alot of ppl who will never learn or seem this way, and you will not be able to change them by being their target of harassment. Just be polite, like a customer friendly business person around those ppl to you, and treat them indiscrimanently from the countless other body masses that you must pass by on your way to class, or your locker. If your soo busy to not pay attention to them either, and just have fun at school and do your thing, the law of attraction should help you out in a way too.
To prevent cases of bullying in school, it is important for the child to be taught a variety of social skills that help in harmonious existence. This you may do by teaching the child to be more assertive, ignore provocation and treating members of both gender equally.