Upward twiddle - Twiddle the hat directly above the head
Use a palm-up fork grip on both sides the hat, and lift it off the head and straight up. Remove the ring fingers from the brim and twist the hat between the fore and middle fingers. Stop the spin by gripping the brim between the fore fingers and thumb.
You can either place it straight back on the head, or reverse the twiddle on the way back down.
From the TricksWithHats Archive
Can Opener - Literally flipping your lid!
Reach over your shoulder and head, and hold the hat in an inverted pinch grip
Flick the wrist upwards and release the hat, which will execute a perfect single spin (honest). Coat-peg catch above your head.
Minus five style points if you have to look...
Plus 10 points if you can catch the hat on your head blind, and without the coat-peg grip.
From the TricksWithHats archive
Place your palm flat on the back of the head for a neck chop and knock the hat upwards with the little finger side of the hand.
A few tries and you will see how much force is required to get it to spin 3/4 and land on your foot. You need to flex your foot as much as possible to stop it slipping off.