Dont get angry, get even...well not quite. But what I like to do it call them on it in front of everyone. You want to see some psychology at work give someone the thought "last time I pulled this crap I got publicly humiliated". Im not talking about if someone says "wassup" instead of their usual "Yo" im talking about "If this person wasnt my friend Id kick his ass" kind of stuff. Also if you just come out and say "hey when you do this it bugs the heeeeck out of me" if its a true friend they will make the effort to not do that to you