I think that I have realized that thinking about getting up in front of people and performing is worse than actually doing it. So I try hard not to think about it too much before hand. I like to do open mic, but open mic still scares the heck out of me. Especially if I sit there and worry about it while I wait. Instead, I try to really listen and enjoy the people before me, and after me for that matter. I don't think about it until my name is called to go up. I also do some coffee shop gigs with another musician. In that case I again try not to think about it. I busy myself with setting up equipment. If we get everything set up early, I get something to drink, go outside and I think about something else. Or I find someone to talk to. And when it is time to start, I start. I don't spend any time thinking about starting. After I get started it seems to take on a life of its own and I don't worry about it at all. Busking for me has to be the hardest. It is hard to get going on a street corner with people coming by. I just start as soon as I get set up. I don't wait for everything to be just right, because it won't. If I do wait, I just get a case of the jitters. So that is my experience. When I started out, I would not sing in front of my wife inside our house.
Of course, knowing your songs really well is important, but even so, that doesn't alleviate that anxiety. One thing is that I'm not a perfectionist, and I don't set myself up for failure by setting expectations for myself so high that I make it impossible to succeed. I went out and did my first coffee house gig with the other musician way before I would have thought that I was ready. I did not realize what I had gotten myself into until it was too late to back out. That is a story in itself. But am both lucky and glad that it happened because it was a turning point for me. I also do not compare myself to other performers. I never think that I can't go up there because someone else is better. There is always going to be someone better than me. All I can do is be as good as I am. If one waits until they think that they are ready, it won't happen. So I suggest that if someone has a couple of songs that they can get through pretty well, just go to an open mic somewhere, sign up, and when it comes time to get up there give it everything you have. You will surprise yourself.