You must have confidence in your ability to make the shot required. This comes from practice. (Byron Nelson, star professional golfer)
Confidence is important for any athlete or artist. As Nelson suggests, you can gain that confidence only by continual practice of your sport or art. But practice itself is not enough. For, while practice may make perfect, as the saying goes, it also makes permanent, so be sure to practice correctly. Then, you can proceed with confidence in your game or art.
In quietness and confidence [in God] is your strength (Isaiah 30:15).