Tells are traditionally associated with people's physical twitches in which one gives away the strength of his or her hand. Tells exist both in the brick and mortar and the online world. Here are some common tells:
Online
• In limit, a quick call with two flush or straight cards out generally means a draw.
• In limit, a quick raise on the flop generally means top pair.
• A poor player who is thinking generally has a weaker holding and is debating a call.
• Generally if someone thinks for awhile and then raises, it is not a bluff.
• Someone who is frequently raising the pot preflop and then folds at the flop if someone bets at him is likely to be on tilt.
Live
• When a poor player puts a hand over his mouth, it generally means he has a strong hand. Generally he is concealing a smile.
• Shaking hands means the player is nervous. However, this can mean he is bluffing or that he has a very strong hand.
• A player reaching for a drink also is a sign of being nervous.
• When a poor player 'stares you down,' generally it means he is bluffing.
• When the flop comes and a player quickly looks at his chips, he is likely to have a strong hand.