Best presentation advice I've heard: put your conclusions first. People zone out after five minutes if they're not interested. Tell people up front what you want them to take away from the talk. Then, even if they fall asleep, they'll know what you did - just not how you did it.

This is in an academic setting, by the way, and that advice was given from the chair of my department to someone in my research group who was prepping for an interview talk at a government lab.