Put the cards in your pocket remember the bottom.

Lets say the bottom card is the 3 of diamonds.

Ask them pick 2 suits and they say spades and hearts if they say that ask them what 2 suits are left your trying to get them to pick your suit they would half to say clubs and diamonds so say pick on of those suits and if they say clubs say whats left and they half to say diamonds and you say thats your suit.

since their card is the 3 of diamonds ask them pick a number between 1 and 4 som if they say 1 and 2 say what 2 cards are left they will say 3 and 4 tell them to pick one of those 2 (3 and 4) if they say 4 say whats leftand they half to say 3 so say your card is the 3 of diamonds.

remember that 3 of diamonds is at the bottom of the deck so tell them to say stop when you want them to pull the card out of the deck when they say stop simply draw the card from the bottom of they deck