Back rolls are a popular intermediate trick . You should be staying upwind, be able to jump and ride toeside before attempting this trick/skill.
As your skills improve its great to learn some tricks. The Back roll is fairly easy to learn and great fun to do! The kite keeps flying in the direction you are going while your body does a shallow loop in the air.
Attempting back rolls can lead to disorientation and crashes
Good power helps with this trick - don't attempt it in light winds or if your kite is small for the condition.
Check that your bindings (footstraps) are well attached
Clearance. Make sure you are clear of obstacles forward and downwind. Keep well clear of other while learning to backroll.
Kite. Fly the kite to 11:00 (left tack) or 1:00 (right tack)
Hands. Position your hands close together at the centre of the bar
Speed. Maintain some speed and begin to edge upwind
Select ramp. Pick a small wave or chop to kick off
Carve upwind. Push hard on your back foot to start rotation
Head. Throw your head in the direction of the loop, lifting your board into the air
Look. Look over your shoulder.
Lift your legs to assist your rotation.
Bar. Keep some pressure on the bar, particularly your front hand, to maintain some height
Spot your landing. Look down to spot your landing
Finish. Touch down and keep going
Tips and things to watch out for
Keep your kite high - if its lower in the power zone you won't get enough height to complete the backroll
Keep your hands very close together or use one hand in the middle of the bar - if they are too wide you could redirect the kite
If you get a big yank let go of the bar
Commit - throw your head into the turn with some gusto, your body will follow
Over rotation is a common error. Try not to rotate too fast - you will become disoriented.
If you are having trouble, try doing the trick without lifting up in the air. You can do this using the same motion, but just keep the board on the top of the water and complete the rotation.
What next ?
Once you have nailed this, it might be time to think about double rotations, air gybe's or forward rotations. You can also progress to a back roll kiteloop.