Trick: A spectator cuts the deck 13 times. You deal the cards into 13 piles (as if you were playing a card game.) You turn the piles over, one by one. The cards in each pile are of the same value.
Be sure you are using a full deck of cards. Before the trick, with no one else there, put all the same cards of the same suit in numerical order. You should have Diamonds in Ace through King order, Clubs in Ace through King, etc. Put the four suits together, just as they are.
Tell everyone how mysterious the number 13 is. Have a spectator cut the deck 13 times. Deal the cards into 13 piles, then turn the piles over.