You can only bluff when there are players in the table that like to play seriously. First of all you have to stablish your power in the table, how you do that? By winning with good hands. Then you settle your dominance by winning more hands but this time without showing the cards (so if a player thinks you are bluffing and calls you till river you show every player that you had good cards). After that, you determine which hands you will bluff, but if in one the players show a bit agressive it's definitely because they have something so you simply fold and try in another. Now the real trick is that you definitely believe having the cards, and in each situation you have to bet how you would bet if you had those cards (which you dont). For example: i determine that this is a good hand to bluff, there has been a lot of action in the table and me, the most powerful player of the table (measured in terms of stack or reputation) havent been participating for a while. So now i decided that my cards are a pair of AA even though the dealer gave me a 4 and a 7. So i raise as if i had a pair of aces, and few call. After flop i do a test bet to check what cards my opponent have but keeping in consideration that i have a pair of aces, so my bet would be 1/2 of the pot. One player folds and the other calls, so its 1 vs 1. Now my bets must be carefully selected, taking in consideration all of the possible aspects that influenced my opponent to call my previous bet (maybe there was a Q in the table and its the higuest pair, so if a K or A do not appear in turn or river my opponent will keep calling (just because he is a bad player or because he knows me), or maybe he is waiting to complete his project, which i have to be careful, or perhaps it's the other way, he is expecting me to complete a project. Well there are a lot of variables, but it's important that you keep notes of your opponents to know the best thing you can do). Suppose you decide that your opponent if waiting for a project, and the turn didnt gave him the card, which means your fake pair of aces still are winning. Now you have to make him fold because you know in river he will get his card, so since each player has a number you bet that number (some players at this stage will simply fold for all ins, or maybe by 100% of the pot, others for 2/3, you determine who is your opponent).
To bluff correctly here are some thing to take in consideration:
* You need power in the table
* You need to know each player in the table, if you don't have notes on someone you dont bluff that someone.
* You need to have a good reputation (a bluffer reputation will definitely make you loose)
* You have to know how to read players. You read players accordingly to the past, notes again. Few players change their gamestyle, so you determine how each player is accordingly to the bets, thats the only way to get information of players.
* Definitely make people feel! Emotions should be discarted in poker, it's just a game, nobody should feel something for some cards or chips. But your strategy is to make them feel, so that makes it more real, and the primary feeling that players have is definitely fear. Good for someone to stablish his power.