If I had a nickle for every time a student said to me, "I will do it when I have an audience," or "I was too busy to practice," well...I'd have a lot of nickles!
In my opinion there is no such thing as perfection, but we can build strong, permanent habits that help us perform at our best. This includes mental preparation as well. Many people forget to prepare mentally for the endurance race competition imposes upon contestants. Practice each phase of competition to the fullest, as if hundreds of people are watching. If you usually rely on receiving energy from the audience to fuel your performance, see how you can create energy by using your imagination and unleashing your spirit and personality free from inhibitions and judgement. You have to rehearse positive thinking and a winning attitude every single day. Always remember "Practice Makes Makes Permanent," so practice in a manner deserving of a crown.
Don't wait until game day to put your game face on.