I learned this trick some years ago from a book of card tricks that I no longer own. I can’t even remember the name of the book to give credit to it. But, of all the card tricks that were in the book, this one has stuck with me, both because of how easy it is to do, but also for the reaction it gets.
The trick works like this:
You fan out the cards, and ask someone to pull one out at random, look at it, memorise it, and not show you. If there are more than 1 person, it’s a good idea to get them to show the others as well. Square up the cards, and get the person to replace their card somewhere in the middle of the deck. Having done that say something like this “If I were an amateur, I’d try to find your card like this” while putting the deck of cards behind your back and making it look like you’re feeling for their card.
Bring the deck back out and say: “But I’m a professional, and this is how I find your card.” Then spread the cards out on the table (or fan them out if you have no table). The person’s card will be face up in the deck. Cue amazement from your audience.
This is a dead easy trick to set up, all you need is the bottom card turned face up. When you fan the deck out all you need to do is make sure you don’t show the bottom card. Now comes for the only minor sleight of hand in the trick. As the person is looking at their card drop your hand holding the deck down to your side and casually turn it over so the bottom card is no on top. It still looks like a normal deck.
When it comes time to get the card put back into the deck it’s important not to show that the rest of the cards are face up. I like to do a small riffle through the deck and ask the person to tell me when to stop and get them to slide their card into the gap, then square the deck up again. No, when you put the deck behind your back all you need to do is flip the current top card over, then flip the entire deck back over the right way up. The comment about an amateur finding the card that way is a nice way to cover up what you’re doing.
Now when you bring the cards back out in front of you, they’re all ready for the big reveal. Since you flipped the deck before the chosen card was replaced, it is now the only face up card in the deck. Quite an impressive effect for such an easy to perform trick.

I like messing with stuff and seeing what I can make it do. Computers, electronics, photography are my main hobbies, but I also enjoy bike riding, gel blasting and music.