Surprisingly, even when players understand bluffing and catch you at it, they often don't credit you with doing anything but trying to pull a stunt. If you bluff and win, you sometimes want to show off, just to upset your opponents. In either case, you're set to take advantage of them by not bluffing for a while. The one mistake you don't want to make while bluffing is going too far. Unless the pot odds dictate that you play, if the price of bluffing becomes too expensive, don't hesitate to throw your cards away.
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There's an art to bluffing, but it's an art that can be learned. Eventually, it comes easily, so practice it. Use a computer or deal hands to yourself and think about how the various ways you might approach a bluff. Put it to the test in small limit games if you can and see what happens. A good bluff can mean the difference between a winning and losing session.