Setup
Take all cards from a suit (the spades for example) and place them in order, first ace all through king. Count 11 cards from the deck face down and place the spades there.
This trick works best with 2 spectators.
You can start by giving the deck some false cuts if you want.
Then, ask a spectator to divide the deck into 3 approximately equal piles, and put them in order on the table for simplicity.
Spectator 1 can now remember the card on top of the middle packet, and shuffle it. Spectator 2 can shuffle the top packet and look at the top card.
Now put the deck back together in this order : TOP-BOTTOM-MIDDLE.
Take the deck facing you and look now for their card. Spectator 1's card is the spade (if you used spades) with the lowest value in the bottom third of the deck. Put it on the table.
Now take the value of that card, add 10, and deal off that many cards from the deck face-up. The card corresponding exactly is spectator 2's selected card.