test your knowledge of regular skills and gain mastery

I completed some work procedures from memory the other day. This struck me as a great tool for personal development. Prove you know something to yourself by performing it from memory. You will gain confidence and uncover weak points that may remain in your understanding.

keep performing, don't dwell on mistakes

Act confident. Be confident. Keep delivering the presentation and ignore your mistakes. Even if the audience notices any mistakes, they’ll take more notice if you lose your composure.