A very wise soul recently gave me this advice when feeling nervous up on stage,

'Look them in the eye, one by one, and give em your best smile.  (Ella, I know its kind of a lot of people to look at but do you best)
Throw your head back and sing from the heart.
Guess if you are playing an instrument, you got to play from your heart too.
Find the back corners of the room and be that big, from the beginning to the end.'

Bonnie