Pay Attention and It Will Pay You

Concentrate on everything when you're playing. Watch and listen ... remember you have to do both, and relate the two. You listen to what your opponent says, but you watch what he's doing independently of what he says because a lot of players talk loose and play tight, and a little later they'll reverse it on you. So you look at a man every time he's involved in a hand. You judge him every time. That's the way you get to know him and his moves.
If you aren't learning what you want to know just by watching and listening, create your own opportunity. Try to bluff at him the first good opportunity, and see if he'll call you or not what kind of hand he'll call with, and what kind he'll throw away. Of course, anybody with a lick of sense is trying to keep you from reading him. But you can still figure him because it is very, very difficult for any man to conceal his character.