My friend was very nearly very seriously injured in an accident last week. He was launching his kite (10m) on a pretty windy day from our kiting spot. A very small beach in San Andres with onshore winds and palm trees. His steering lines were tangled on one side and when launched the kite flew up hard and fast and flew into the palm trees behind him on shore. The kite whipped him up in the air and he crashed into a palm tree stump hitting himself in the neck. He couldn't move for 5-10 minutes while the ambulance came. Luckily he suffered no major injury but will not be able to kite for several months. He is an experienced kiter, about 100 kilos and has kited at that beach for years.
So............check those lines visually before you give the signal to launch the kite. take the extra couple of seconds to be sure everything looks ok. Toby's method of one hand on the bar, one on the release makes sense. I still see guys launching their kites with one hand while holding their boards in the other. A helmet wouldn't have helped in this accident but if he had hit the stump a couple of inches differently it would have probably saved his life.