Cut a piece of string so it's the length of your shoulder down to your hand.
Cut a small piece of tape and attach it to one end of the string. Tape it behind one of your ears or a shoulder.
Cut a small piece of tape and place it on the other end of your string. Tape that end to your card.
Spin the card outward and away from your body. This part could take practice as you'll have to know how hard you need to spin it and the stance you need to take so the card doesn't bump against you. A slightly bent over position with one hand a few inches above and the other a few inches below the card creates the most believable effect. As a final but vital part of the illusion, wiggle your fingers as the card dances around. This should leave the impression that your fingers are making the card move even though they're not touching it.