TIP #1 - USE YOUR HEAD  
First, stay calm and think as the situation develops. If you are calm, if you do not panic, your mind will process thoughts so rapidly that it will seem like you have hours to make a decision about how to react.

Second, the human skull is an awesomely powerful weapon. Bashing your forehead into the goon's nose once is tremendously more effective than slamming your fist into his nose twice.