Preparation
Researchers at the Technical University of Munich have found a simple and quick
prevention for choking. By squeezing a ball dynamically in the
left hand for 10-15 seconds, a relaxation effect is stimulated in the brain, thereby allowing a move to be performed fluidly. To date, they have seen positive outcomes with tennis, badminton, beach volleyball, soccer, golf, tae kwon do and gymnastics. You can view a full interview with the lead researcher
here.
I'm not a fan of "hacks," but this technique seems like a simple and rapid approach. For those who are curious, the research has focused solely around right-handed players squeezing their left hand. Squeezing the right hand doesn't seem to work, but it has not been studied with left-handed performers.