As you play, one of the single best things you can do is observe your opponents, even when you’re not in a hand. If you know that one player always raises in a certain position and another has a poker tell when he bluffs and a 3rd folds to every re-raise, you can use that information to help you decide how to play against them. Once you know that player 3 always folds to a re-raise on a river, that’s when you can bluff and steal a pot.