UFC's Chuck Liddell's bar-fighting tips

You know, threatening you by saying, "I'm going to kick your ass!"
You respond: "OK, whatever bro."
A lot of it has to do with being confident in yourself and not really feeling the need to prove yourself all the time.

If you're attacked, strike vulnerable areas, obviously.
I always say look at "He Got Game," the one where Denzel Washington comes up to a guy, and the guy starts getting in his face, so he just hits him right in the throat. The guy can't breathe.