Unlike most of the gambling activities present in casinos, poker is one of the few exceptions to the game of luck. Though poker may seem to be reliant on luck, it also involves a game of technique and skill in predicting the cards of your opponents (relying on probability) and bluffing. The art of bluffing is a very complicated technique that all factors must be considered before the player can accurately use it to his advantage. However, it may backfire depending on how often a player uses it.
When I used to play Poker I bluffed a lot, It didn't end well for me, I lost around 200$ years ago playing poker which doesn't now.
Then I reduced bluffing and started learning about the game watching Negrano's course, which I still haven't finished.
Daniel Negreanu- considered to be one of the best players in poker! Remember that the art of bluffing is a very complicated technique where a hard and absolute rule does not exist. It must be studied and used on a case-to-case basis as it depends on how your opponents react to other people's bluffs too.