This is a simple yet mesmerizing magic trick anyone can learn in a short amount of time. You will need a regular deck of playing cards and time to practice the deceptive card motions for the trick. A dazzling intellect is never a bad thing to have either.
Before viewing the instructions, watch the "Good Relationship Magic Card Trick" in the attached video.
Step 1: Show the Deck
Before the actual trick starts, show the recipient the deck by fanning out the cards, face up, and reassure them that the deck of cards is normal.
Step 2: Explain the Trick to the Recipient
Explain that the trick is dependent on the recipient having a "good relationship with the card" they will be picking in a moment.
Step 3: Quick Slight of Hand
While explaining in part the trick to the recipient, slip the bottom card of the deck and cup it in your opposite hand so it can't be seen. Then, naturally put your hands together, thereby placing the card in your opposite hand, face down on the bottom side of the deck. This will result in the deck looking like all the cards are face down, but in reality only the top card is face down while the rest of the deck is face up, but hidden.
Step 4: Have Recipient Draw a Card
Flip the deck over so all the cards (but one, the bottom one) are face down. Fan the cards out and have the recipient pick a card. Be careful not to fan all the way to the bottom card since it's turn face up. See the video in step 6 for a demo.
Step 5: Explain the Card While Doing Slight of Hand
While the recipient is looking at the card, explain the "relationship" they need to build with it. While they are looking at the card, turn the deck over (at this point both cards on the top and bottom should be facing inward toward the rest of the deck) so all but the top card are face up. This gives the illusion of the whole deck being face down. See the video in step 6 for a demo.
Step 6: Have Them Insert the Card Into the Deck
Holding the deck with all the cards in full alignment with each other, have them insert the card somewhere in the deck. The deck being aligned here is crucial to the trick since you're trying to make them think the whole deck is face down. See the attached video for a demo on steps 4, 5 and 6.
Step 7: Explain What the Card Will Do While Doing Slight of Hand
Now explain to the recipient that "if" they have a good relationship with their card, they will be able to make the card flip in the deck while being shuffled to be the only face up card in the deck. While explaining this to them, do the same slight of hand move done in step 3 to turn the illusion card on the top of the deck, to match the rest of deck (minus the card the recipient drew). See pictures for a demo.
Step 8: Shuffle the Deck
Make this as dramatic as possible by milking the mystery behind what the card "is doing". Many magic trick spectators don't realize when a trick has actually taken place. At this point of our trick all the work is done, but they don't know that so make the shuffle seem integral to the trick.
Step 9: Fan Out the Cards and Enjoy
Explain that if they were able to build a good relationship with their card in the short time together, it will be the only face up card in the whole deck. Fan out the cards and watch as they are caught completely off guard.
Step 10: Don't Reveal How It's Done
This is more important than most mediocre magicians realize. Never reveal how the trick is done. As Christian Bale's character in The Prestige says, "Never show anyone. They'll beg you and they'll flatter you for the secret, but as soon as you give it up...you'll be nothing to them...The secret impresses no one. The trick you use it for is everything."