I have written before about presentation skills and presence and how to improve one's abilities. A further suggestion is to read directors' commentaries on DVDs. For instance I have recently watched and listened to many of Joss Whedon's commentaries on the Buffy the Vampire Slayer. It's interesting how he sets up shots, creates a mode, draws viewers attention to various points. Now lightng schemes might not have much relevance to business presentations, but the discipline of thinking about how you wish the audience to react is transferrable.