Practice until you can perform in your sleep. Regardless of what you're performing, the more you rehearse the better you'll be. But be careful not to memorize your mistakes. A mistake accidentally repeated over and over is more likely to appear in your performance. Perfect practice is more likely to yield perfect results.
Perform for close friends or family. The more you perform in front of people the more prepared you'll be in front of a crowd. Invite a few people to watch one of your practices. Try to perform exactly as you would on stage and then ask for audience feedback.
Ask for an expert's opinion. If possible, find someone who can give a knowledgable critique of your performance. This will not only improve your performance, it can give you an added boost of confidence.
Take note of your trouble spots. Highlight the lines in your script that you easily forget or circle the difficult measures in your music. Practice these areas over and over again until you can perform them perfectly every time. But remember, even with proper practice, sometimes nerves can trip you up. Try associating catchy phrases, acrostics or funny mental pictures with these mistake-prone areas of your performance. This can help to alert your mind that a difficult part of your performance is coming.
Get adequate sleep prior to your performance. According to CNN.com, sleep deprivation is as bad as alcohol impairment. It can severely inhibit judgment and reaction time and cause stress and anxiety.
The day you perform, try to relax as much as possible. Find a friend willing to give you a massage or spend the morning at a spa or doing an activity you enjoy. Also try brief exercise and then a long, slow stretching session. Right before you perform remain calm and breathe in slowly and deeply.
Eliminate possible distractions. Being hungry, thirsty or needing to use the restroom during a performance can cause your mind to wander, not to mention cause discomfort. Eat a healthy snack and drink plenty of water prior to your performance. Right before you go on stage, be sure to stop by the restroom. Also, save yourself any embarrassment and don't consume anything that could cause flatulence such as beans, cabbage or broccoli.
Make use of your spare time. If you have to wait backstage before you perform, don't goof off or waste time thinking of all the things that could go wrong. Try to run through the script in your mind or hear the music in your head. This will keep your performance at the forefront of your mind and help you to focus.
Expect nervousness. Even the most experienced performers can get butterflies in front of a crowd. Instead of letting this hinder your performance, channel your jitters into energy for your act.
Appear confident. Remain calm, hold your head high and smile. The more confident you appear, the more confident you'll feel.