Put the top right corner of the card between your middle and your ring finger on your right hand. If you puut the top right corner of the card closer to your hand it will go right, closer to your finger nails and it will go left, so keep it towards the middle.

Then you want to bend your wrist toward your body until the bottom right corner is touching your palm or below your palm touching your veins.

After that, all you have to do is flick your wrist really fast towards whatever you're rying to hit.

The best way to keep it in one direction is to make it spin faster by holding the card closer to the tip.