Use your Body Too
It has been estimated that more than three quarters of communication is non-verbal.
That means that as well as your tone of voice, your body language is crucial to getting your message across. Make sure that you are giving the right messages: body language to avoid includes crossed arms, hands held behind your back or in your pockets, and pacing the stage.
Make your gestures open and confident, and move naturally around the stage, and among the audience too, if possible.
Find more at: http://www.skillsyouneed.com/present/presentation-tips.html#ixzz4Nb4cPCAl