The group I have been with do a lot preplanning, former/active military. In the military we have forms that must be filled out to include inspections before every jump. We pretty much have them memorized. We check each other's packing procedures (we have two riggers in our group), we do equipment checks before boarding and a quick self check in flight. I also live near a wind tunnel and we practice emergency proceduress (collisions/unconscious jumper) and link ups. The wind tunnel and our chute warehouse has roller boards we practice on. They are pretty much what mechanics use to roll underneath your vehicle except we lay on our stomach. So everything is thoroughly practice on the ground first. We use apps to track weather and wind speed/direction so we can calculate drift and we check with the pilots to make sure we are all on the same page. We all wear helmets, but if your burning in it's not going to save your life. Most people I jump with wear two altimeters, one with a bluetooth ear piece that gives altitude warnings. There are arm and hand signals as well. It's not just flying over the DZ and jumping.

That being said shit happens.