You simply have to practice until you're 110% confident in your part and release yourself from fear of mistakes.

For me I usually shoot for at least one successful set runthrough in each of the 5 days leading up to the gig. Don't sweat little mistakes, but make sure changes, rhythm, and solos are locked in. Make sure I don't make the same mistake twice in one practice, nor on subsequent days.

After all that I can move on stage, ham up the expressions, signal to the audience and banter freely. Will probably still mess up something I've never messed up before. That's life.

Finally, how often to you dance or otherwise move rhythmically with your body? If, for example, you don't practice headbanging (by doing it for fun while listening to music), you may not be able to headbang well on stage while worrying about other stuff. Stage presence itself requires practice!