Let's say that the spectator thinks of the number 12. He counts down to that number in the deck dealing a card for each number. When he reaches 12, he turns over the card. Lets say that the card is the two of clubs. You point to an envelope that has been in full view the entire time and ask the spectator to open it. Inside, a note says "You will pick the two of clubs." You have successfully predicted a card that your spectator randomly selected.

