Are there proven ways to help prevent bullying?

"carry a big stick" Find a friend of substantial size. Learn self-defense. Learn not to engage people you don't know well - even avoid eye contact or walk away if necessary. Report those who engage in this behavior immediately. Make a point of avoiding them and their whereabouts. Others might find that firm resolve, upright posture, and a steady hand - being firm and unafraid - can help.
Yes. Schools with antibullying programs where parents, teachers and the community are committed to ensuring that every child feels safe and learns at school have fewer problems with bullying than those schools without. Stopping bullying in our schools is not just a school issue but requires all hands on deck.