Interesting article on the science of choking. Here’s how to avoid it:

• Practice a lot.
• Once you’re proficient, don’t think about specific mechanics of the motion you’re making. Instead, think about general adjectives or goals. For example, think “I want an outside-in huck to the middle of the endzone”, not “I need to snap my wrist hard”. Specifics are for practice, and the goal of practice is to encode the motion in muscle memory so you don’t think about it during the game.
• Don’t forget to have fun. When you stop having fun, you start to think too much, and that’s when you choke.