When you first begin to prepare your presentation, you defined an image that you wanted to present. “What do I want them to remember of me?”
Who are you? How will you be remembered after this presentation?
Everything the audience sees needs to reinforce that image – clothes, facial expression, stance and gesture.
At its most basic this means projecting confidence and sincerity. Unless you decide otherwise, the audience needs to know that you are comfortable with your message and that you believe in it.
If you are also using this presentation to present yourself as the face of your business, or as a candidate for a position, then take that into account as well. You need to be seen as trustworthy, competent, at ease with your material.