A player who does a one-handed shuffle with his cards against the table (after having looked at them) is probably weak.
I see this tell a lot pre-flop in Hold’em. Players do a one-handed shuffle of their cards when they are planning on folding. I think it’s probably just a nervous release of energy—something to do while you wait to fold. Think of it this way; a player with a good hand will generally not want to draw attention to himself at all, even in such a small way.
I find myself doing this one a lot; that’s how I initially came to notice it in other people.
A player who is feeling uncomfortable will not usually smile genuinely.
If you’re in a significant pot and a player doesn’t want you to bet, he will be unlikely to exhibit a real smile.
EXCLAMATIONS ABOUT BOARD CARDS
A player who makes a spontaneous exclamation about board cards is very unlikely to have connected very well with those cards.
When it’s a multi-way pot, and a flop comes out with something like Jd Qd Kd or the turn puts three of a kind on the board, you will sometimes hear someone in the hand make some sort of instant exclamation, like “whoa”, or an impressed whistle, or something like that. Or maybe the flop comes up 66x, and someone laughs and says, “Sixes again? Sixes are hot tonight!”
In my experience, 95% of the time, a player who makes a sudden, spontaneous exclamation like this will not have connected with the board in a significant way. They may have a good hand, but they won’t have the trips, or the set, or the quads, or the flopped flush, or whatever the super-strong hand would be in the situation.
This tell is surprisingly accurate, even for higher-stakes games where you would think the tell is so obvious that players would be more careful. In low-limit games, it is very useful. I can really only remember a couple times in all my years of playing where a player who made a quick exclamation about the board actually showed up with the goods.
Think about it this way: players who actually connect hard with the board will not want to draw attention to themselves. When someone suddenly stumbles across a super-strong hand, his natural, immediate instinct is to stay quiet and hide that information from others.
Again, this tell is typically useful only in multi-way pots. Players in multi-way pots are more likely to have their guards down, and more likely to make comments about the game. In heads-up situations, players are more buckled down and try not to give anything away.