1) You can stack an extra deck & hide it in your pocket.Mark the high cards in the deck by cutting through one part of the deck with the tip of your fingernail.Then switch out the decks at the table.

2) Take a good card & hide it underneath your leg.Switch the good card with you have hidden.Make sure you keep the card hidden from the other players.

3) Carry a reflective object like a pocket watch or a pair of reflector sunglasses & place them on the table in front of you.By moving the object around the table or adjusting it in your hands,you might be able to see what the other players have in their hands.

4) Bring along your own supply of chips in your coat pocket.Make an excuse to use the restroom & take your chips with you.Then you can easily add to your stack without anyone seeing you do it.