Chest spin - Spin the hat down the arm, across the chest and out along the other arm.
Hold the hat crown down in a outside grip. Flick the wrist inwards as hard as you can so that the hat spins fast and strikes the inside of the wrist. Allow the spin of the hat to carry it across the body and along the other arm. Catch the crown as it reaches the other hand.
From the TricksWithHats archive
Three Hat Cascade - Ring Style - Juggling 3 hats in a cascade, throwing them as you would rings.
1. Learn to juggle 3 balls. See the IJDb tutorials page. Sorry non-jugglers, but it'll help a lot.
2. Throw each hat with a flick of the wrist to give it some stabilising spin. Catch the hats palm-upwards, in an inside grip. Rotate the wrist inwards 180 degrees before the next throw.
Tumble - Tumble the hat over the back of the hand
Hold the hat crown up in a outside grip. Swing the hat inwards and let go so it can roll up past the thumb onto the back of the wrist. While the hat is above the hand keep the wrist bent so the fingers are pointing outwards and lift the fingers as high as you can. The fingers will touch the inside of the crown and allow you to catch the hat in a inside grip.
To repeat the trick throw a half spin and catch the hat back in a outside grip or do a Reverse Tumble.