It really depends on how bad of a position you are in. f you have only a small handful of chips, it is obvious that you will be bluffing. You have too. You should bluff when you are in a good position or a moderate position, never bad.

That's a part of my game that I'm not too proud of, my bluffing skills. Every once in a great while I can fool someone but it's not nearly as often as I would like