One of the most important aspects of PowerPoint delivery and success for PowerPoint delivery is Sequencing. What do I mean by that?
I think of how most people use their PowerPoint: they throw up a slide, they look at it, and then talk about it- maybe go into a little bit of detail, and then move over to the next slide. Usually their slides are driving the show and that is the wrong way of doing a presentation.
The best way of sequencing things is for you to stand up, introduce your concept without a slide, and give facts with examples. Tell your audience a story, give them a few details, and basically make your concept come alive in front of their eyes without the aid of anything else other than your voice and your ideas. Only then should you put up a slide that then drive the point home even further and further implants it on the memories of your listeners.
So as you can see, the most effective way of using PowerPoint slides is the complete opposite of how it is normally used by presenters. You are the one giving the speech and ideas, not your PowerPoint slides.