The less tension and effort, the faster and more powerful you will be.
If you’re an athlete, go back to a time when you were performing at your peak. Notice how you weren’t exerting that much energy? Weren’t you “just” doing it?
Be loose, clear your mind. But be focused.
When you are practicing, you should think about your technique.
When you are competing, you should be more automatic.
Take a deep breath and trust your game.