I've been using this one at my local casino, particularly when a player has made a focused gaze at me after a bet. If I have put a player on a specific hand or holdings I will say you got pocket 99's over there. If that player is holding pocket 99's they will become confused and a lot of the time break their fixed gaze and the eyes will soften slightly almost as if a tear is coming and the capper is a slight mischievous grin on your opponent. They are doing this because if you have called their cards out for a brief moment they will not know what to do and give off some of these clues. This also works if you have second best hands. Get a friend and rig the deck without him knowing it. On the third heads up hand call out a holding you know he doesn't have, then call the holding you know your friend to have.

Idk how reliable that is but it's a good way to let someone know you don't have pocket 9s.

I played with a guy who would try and call people's hands all the time. It didn't take too long to discover that his clever little secret strategy was that he was actually announcing his hand to the table every time he did this.