btw what ponraul said about keeping eye contact etc...is incredibly true.

your body langauage is fundamental in situations like that.

if you walk around with your head bowed and shoulders hunched you literally look weak and like a target as opposed to someone who walks with a confident aire.

if any sort of argument or whatever breaks out the way you conduct and carry yourself can make the best out of a bad situation. Keeping calm and not looking intimidated can and will put alot of people off trying anything and will usually work better than getting scared or trying to act mental trying to scare the assailant (unless you're really sure they'll back down 1st)