Here are 10 proven rules to improve your presentations whether you make them in PowerPoint, Prezi, Keynote or other medium. Sometimes I witness people struggling more with the medium than with the message they plan to deliver. Remember, all those sofwares mentioned are supporting medium.
Concentrate on the message. Starting by writing down which goals to achieve and what information to display on paper. The rest will follow. And last but not least, practice in front of the mirror.