Cut a piece of magician's thread that runs the length of your earlobe to your stomach. This is the default length: it can be altered for your needs and preferences.
Attach magician's wax to both ends of the thread. Stick one end of the thread to the back of your earlobe. Stick the other end to the back of your thumbnail.
Give the pack of cards to one or more of your audience members. Allowing them to see that the pack of cards is real and unaltered helps your illusion to appear real as well.
Stick the magician's wax to the center of the top card while conversing with your audience. Tilt the stack of cards up so that you can hide your thumbs behind it, then use your free thumb to remove the wax from your other thumb and secure it onto the card. Start a lively conversation while you are doing this: it will allow you to attach the string to the card while distracting your audience's attention from your hands.
Spin the card by throwing it into a spin. The string will allow the card to spin without your hands touching it, giving the illusion that it is levitating. This is the easiest way and is recommended for beginners.
Flick the card to give the spin a more controlled appearance. To do this, hold the deck of cards in one hand and, with the other, hold on to the top card without lifting it too far above the rest of the deck. Grip two outside corners of the card with your thumb and index finger and release it by placing pressure with your index finger until it releases.
Control the card by immediately catching the string inside the v-shape that is formed between your thumb and middle finger. Resting the string here will allow you to maneuver the card around flawlessly while maintaining a high level of control over it.