Poker Tells
A Poker Tell is any habit, behavior, or physical reaction that reveals information about your hand to other players. There are many contradictions and exceptions to the rule in poker but there are some tells that are commonly known to all poker players. Another good article to supplement this is Facing Unskilled Texas Hold 'em Opponents as not only the tells that can show you where the wholes are in other players strategy - sometimes it there can be a complete lack of skill.
The Eyes –
Eyes have always been known to mirror your thoughts and as the saying goes eyes never lie. That is why many pros wear sunglasses or visors/caps when playing so that their eyes are not visible for the other players to see. It is common for players to quickly glance at their chips if they connect with the board after a Flop for example. This may be a subconscious reaction, but the player is already planning his attack.
Facial Expression -
Many pros try to disguise their entire face by wearing a cap and looking downward in order to avoid the classic stare down that poker pros are famous for. They may try to study your face for nervousness or even look for repetitive characteristics like a body "tic". You expression may reveal unhappiness when your hand is weak, and conversely, you may show confidence when your hand is strong.
Weak is Strong/Strong is Weak –
This is perhaps one tic that most players whether novice or professional succumb to sometime or the other. Basically, players like to be actors, and when they have a really good hand they tend to look disinterested. Alternatively, a player increasing the level of his voice while raising the pot, and trying to look intimidating may be running a bluff.
Anxiety –
When times are bad or during confrontational situations, anxiety sets in and physical changes like flexing of muscles, eye pupil dilation, palpitating heart rate, dry throat etc tend to occur. Trembling hands are one of the most common by-products of anxiety, perhaps signifying a big hand or simply a nervous gesture.
Peeking Hole Cards on Flop -
Some players will take another look at their hole cards when, for example, the board is showing a potential 3 card flush draw. Typically, the player is looking to see if one of his cards is connecting, because he remembers only that the two cards are different suits.
Repetitive Betting Patterns –
The most revealing tell is when a person bets the same way repeatedly during particular situations.
Body Posture v/s Attitude -
Some players show obvious changes in their posture based on their attitude and hand strength. For instance, shoulders slump when you have a weak hand or you tend to become attentive when your hand is good.
Chip Stacking
When you sit down at a table, study the way the players stack their chips. Loose aggressive players typically maintainsloppy stacks, while tight conservative players keep well organized and neat stacks.