- if somebody has a good hand, he's likely to keep himself to himself;
- if somebody has a bad hand, he's likely to look around the table at the other players to see if he can pick up any clues from their physiognomy;
- the best players never bet everything they've got on a hand - they bet moderately to string others along;
- the answer is to develop a uniform appearance, be patient and always do exactly the same thing, no matter what cards you have;
Seu Francisco is a former Brazilian Poker Champion, and thus should be lent multiple ears, in my humble view.