An unhooked backroll kiteloop, also known as an F-16 is a great progression trick from a simple unhooked backroll. You should feel comfortable with unhooked backrolls and unhooked kiteloops before you attempt an F-16.
When learning this you'll want medium pace with small loops. Small loops are achieved by pulling really hard on one side of the bar with the bar sheeting all the way in.
This trick is all timing and practice. If you feel good about you unhooked kiteloops this will be a relatively easy trick to add your your Kiting.
Ride into the trick with medium power, unhook and change your hand grip to the "fishing pole" position, where you change your front hand to the bottom of the bar. This will initiate a fast kiteloop perfect for throwing your F-16.
Now edge hard and take off as though you were throwing a normal unhooked backroll. You will start to feel your kite pulling higher as your takeoff for the backroll. You want to leave the water as your kite is dipping down into the loop. Keep your fishing pole hold on the bar and commit to your kiteloop. Letting go of the bar will cause your kite to crash straight into the water, and probably give you some extra whiplash.
Hold on through the loop and spot your landing as soon as your head comes around. If this is your first unhooked backroll kiteloop you may be find yourself higher than expected, and that's great, just keep cool and keep your eyes on the landing.
Be ready for the biggest backroll you've ever done. Expect to have completed the roll by the time the kite is in the center of the power zone.
As you land bend your knees to absorb the impact, and as soon as you can release the fishing pole hold for a normal grip, otheriwse your kite will quickly go into another loop.
Ride downwind and hook back in. Awesome!