hmm. the best comedians tend to be combinations of these:
A) smart.
B) observant.
C) funny (this one is quite important, actually).
D) (optional) musically inclined.
also, watch lots of stand-up comedy (if that's what you're aiming for), and learn from them.. the way the present themselves, their gestures, their facial expressions, how they draw in the audience, etc... etc..
a few of my favourites are:
Ed Byrne
Stephen Lynch
Eddie Izzard