learn some martial arts, carry some pepper spray, watch your drink, get that nail polish that changes color when you did it in a drink and it detects a date rape drug, don't party to the point you can't function, carry a lethal weapon or baton and know how to use it, travel in groups of people you trust, use common sense.
Yes I have, actually. I'm sad to say I lost contact with her, but I think she learned to not get too messed up at parties, at least that's what I hope has happened.