Boomerang

Start the boomerang with a Sleeper, about halfway through, fold the string over your left hand finger and "throw" the yoyo forward by bouncing it off the string above your right hand.

In order for the yoyo to fly forward, you need to move your right hand closer to your left hand. Try to move closer a little at first. When you are confident in the trick, you can try to do it so that your hands touch. But be careful of burnt fingers!