I kept dinging the nose of my board with catapults while learning, then watched a Dr Beats instructional DVD and he said never let go of the boom, didnt ding a board for the next 4 years......until a couple of weeks ago at 33 knots over 50cm harbour chop.
Keeping hold of the boom pushes it leeward of the board when it goes, letting go makes it slam with force straight onto the nose. Sheeting in half way through also makes it clear the nose, and is the first half of the loop.
To avoid them it comes naturally, at first you learn to luff the sail, letting go with the back hand.....then less and less you do this and keep the power on as luffing it you lose all power and at first can be difficult to recover without dropping in the water with a mast on your head