One thing a performer always need to keep in mind is ?

For me where you look is very important.
Your Eyes tells story more than anything you do on stage.
Wether you look at audience or look at something else or even close your eyes.
It will be your choice but it changes the feel and dynamic of your performance.
Eye contact! with your audience? with your musicians? with other performers on stage? or with yourself?
It is how ever you like it to be, but be aware :)