Bluffing is an art that takes minutes to learn and years to master. The biggest part of bluffing is knowing when to do it and when to just check it down. The tighter the player the more apt they are to fold a hand to a proper bluff. There are many things that helped me. First and foremost is experience. I've played 100's of thousands of hands and I've slowly started to master the art of bluffing. Another thing that helped me was getting a tracking system. It tells me how often a player comes into a hand, giving me a measure of their tightness. Like I said, the tighter a player the easier it is to bluff. Another thing that helped was learning how to assign ranges of hands a player could play and looking at them vs the board infront of me. This helps you see if the board helps them.

The first bluff move to learn is the continuation bet. Say you hold AQs from late position. You raised after a mid position limper to 3.5x the bb. You get the BB and the mid position limper to call and see a flop. The board comes K 5 7 and it checks to you. This is a great time to make a continuation bet and see if the pot is yours. You bet 2/3 the pot and it folds around. Great "bluff" that picked up the pot.

It's easy to know when to bluff, but it's harder to figure out when NOT to bluff. That information can be the difference between losing a small pot and losing a big one.