In the weeks previous to the performance event, prepare yourself as thoroughly as you can in your practice. Go over and over the pieces. The phrase “it’ll be all right on the night” is meant as a joke. Without lots of preparation it won’t be all right on the night.
Check you have memorised well.. Fear of forgetting is the greatest source of insecurity.
If you are reading from the music, make sure in concert you look at your hands or at the fretboard in the same places as you do when you practice.
Practice difficult phrases by themselves very slowly until you can play them at your desired speed five times in a row without errors. If you can’t, choose easier pieces.
Go over the pieces in your mind in the weeks before: that includes fingering patterns, musical notation, phrasing and overall feel.
Keep playing the same pieces in different events. They will get better and you will gain hugely in confidence by so doing.
The more often you play to others, the more likely you are to control those butterflies in the pit of your stomach, and the shaking hands.
The performance is not an exam, it is an experience shared equally by everyone present. If you prefer you can think of it as a circular experience: the listeners transmit their best wishes to you which help make you feel good. You in turn move them with your playing, which leads to the listener communicating their pleasure back to you.
Think positive thoughts before and during playing. Inside us there is a war going on between a positive voice and a negative one. Keep talking up your positive voice, and knock that negative one on the head for it is very destructive and undermining of your self-confidence.
In performance breathe deeply, concentrate on the spirit of the music and the mood you wish to create. Everything else will take care of itself.
Playing in public is an emotional roller-coaster. Our feelings during and after often bear only a slight resemblance to the actual performance. Some convince themselves that their disastrous appearance was nothing of the sort, that it was wonderful; mercifully these types are not frequent. More often than not there is an opposite reaction: a huge disappointment at having made a series of crashing mistakes. To everyone else of course, they were just minor blips. A cool-headed self-appraisal is the thing to aim for; that is the way to stay sane, and really improve into the bargain.