This is a card trick I learned years ago from a cousin. Here's how it's done. All you'll need is a deck of cards and at least one person to try it on.
Step 1: Draw a Card From the Top of the Deck
Draw a card from the top of the deck and remember what the third card you put down is. In this case it is the seven of hearts. Keep drawing cards, however, until the guesser says stop.
Step 2: Shuffle.
Split the deck in half and shuffle. Make sure that the third card is on the right on the top of the right side as shown in the picture.
Step 3: Fan Out the Cards.
Fan out the cards and choose a card for the guesser to see. IMPORTANT: You must choose the third card from the right, which is the seven of hearts; otherwise, the trick will not work. This assures that you know what their card is from this point on.
Step 4: Give the Card to the Guesser.
Give the card to the guesser and have him/her show anyone else. Look away or close your eyes (or both) to assure your guesser that you're not looking. Have them put the card back into the deck, anywhere in the deck. For added effect, have the guesser shuffle the deck in addition to your shuffle.
Step 5: Pretend to Look for Their Card.
Look through the deck with a sort of fake confidence. This is very important. You know that their card, in this case, is a seven of hearts.
Step 6: Ask the Guesser "Is This Your Card?"
This step is the very, very important. After pretending to look for their card, pick a card that you know is NOT their card and ask them "Is this your card?" In this case, the card I chose was the Jack of hearts. The card you choose does not matter as long as it is not their card, the seven of hearts. They should tell you that it isn't their card. Act surprised and ask them if they are sure. They will assure you it is not their card. Continue to act surprised and place the card face down on the table.
Step 7: Repeat Step 6
Repeat Step 6 four more times, doing the same thing, but each time, acting more frustrated and more shocked that you're getting the guesser's card wrong. This leads the guesser into thinking you have no idea what you're doing, but in a few steps, you'll see why this is important to do.
Step 8: Look for Their Actual Card This Time.
This is the final time you will "look" for their card". Locate the seven of hearts. Place it so that it is now behind the first face up card in the deck, as shown in the second picture. In this case the first face up card in the deck is a two of spades.
Step 9: For the Last Time, Ask "Is This Your Card?"
Show them the first face up card, the two of spades in this case, and ask "Is this your card?" for one last time. Make a huge fuss about it and make the guesser believe that you believe that their card truly is the two of spades.
Step 10: Sleight of Hand
This is probably the most important step of the entire trick. As you go to put the card face down, push the two of spades back a little and pull out the seven of hearts so that the guesser cannot see as you put it down. Now you should have six face down cards.
Step 11: Start Flipping Over the Cards
Act super surprised that you guessed six times and each guess was wrong and start flipping the cards over one by one until you get to the last one. All the while, keep asking if each card is the guesser's card. Keep asking if they are sure to build up the effect of the trick. Once you get to the final card, which you know is the seven of hearts, ask again, "Is this your card?" They should be amazed that you got their card right!