Bluffing

The art of bluffing, as experts play, is seen in some of the biggest games, where a player with a weak hand forces another player with a stronger hand to fold. Ultimately, whatever you do that helps you win a hand or a game of poker is something to at least be aware of. Control over your expressions and emotions is an important aspect of bluffing. Hide your cues, or tells, that you give off when you pick up a strong hand or a weak hand. Keeping other players from seeing your strengths and weaknesses is the first step in being able to bluff effectively. Acting predictably can also help - your opponents are watching your behavior as much as you are watching theirs, and they will try to pick up patterns of betting and action. If you always fold on weak hands, they will assume that you have a strong hand if you don't fold the next hand. This is when bluffing can let you fake your way into an advantage.
Know the cards well - if you are playing a version of poker that uses community or other face up cards, make note of which ones are showing and which ones you could have that would make for a powerful hand. For example, when playing Texas hold'em, when you see an ace, a king, and a jack get turned up as the flop, you could bet as if you held the missing ten and queen for a royal straight - a powerful hand that would allow other players to think you are very serious if you decided to bet everything you had at that time.
Betting, when done, is done as if you had a stronger advantage - betting higher than you think you should in order to intimidate others from following your lead. Of course, timing is everything - it may be too late to try to bluff after your opponents themselves begin betting high values. If they are betting high, you may assume that they are either bluffing themselves or in fact holding a strong hand themselves. You would likely have to raise the stakes very high to intimidate someone in a final round after they had already contributed a large amount into the pot, and coming on too strong may give your opponents a clue that you are, in fact, bluffing.

Detecting a good bluff is done using much of what you've already learned: look for initial tells and patterns of behavior that give you an idea as to what your opponent is holding. As they say, the first flinch is likely the right one - a player may leak out a tell before trying to cover it up with forced bravado. Watch for the cards that come out and know what cards they may be shooting for to figure the likelyhood of them actually having that hand. Remember that a player will want to win as much as they can when they are holding a strong hand, and they won't be able to do that if they scare everybody off on the first round of betting, so don't bet too high if you're bluffing, and watch out for an opponent doing the same thing.