Three card is a classic game of skill. Speedy hands versus speedy eyes. Although there are many different techniques for dealing three card, this is the one I grew up with.
Step 1: Preparing the Cards
Before you can begin dealing, you must slightly bend the cards along their vertical axis. Not too much but enough so they will stand up off of the table enough to grab easily.
Step 2: The Game.
I chose two black kings and the queen of hearts. The point of the game is for the dealer to shuffle the cards and for the player to try to guess which is the queen. With just a bit of hand eye coordination and misdirection the dealer can make following the queen nearly impossible.
This is how the round starts. I grip the kings between the inner half of my pointer fingers and thumbs with the queen between them just to show the player that there is nothing fishy going on.
Step 3: The Moves.
To begin the round, I flip the queen over and pick it up with one hand and show it to the player. I then throw it back down and pick it up with the other hand. I will pass it back and forth as such for four or five passes.
Step 4: The Throw
The key at this point is misdirection. Pick up the queen as before but this time throw the king instead. It takes a little skill to let go of the upper card but nothing a few tries can't figure out. If you've done it right, the players eyes will naturally follow the wrong card.
Step 5: Shuffle and Choose.
The key is to not pause after the throw. Just toss the king and immediately start shuffling the cards back and forth switching out the side card for the center card alternating left right left right. After several shuffling passes, you give the player a chance to choose...
Step 6: The Win!
Let the player make their choice! Hopefully, they can't find the queen!