Demonstrate Confidence Through Command Presence
Improving Your Command Presence (lawofficer.com)
Easy Trick: Black Slide Technique
Prepare a couple of completely black slides in your presentation. When you audience the audience to pay attention to you instead of the slides, bring up this black slide.
Alternatively during the slide show mode in MS PowerPoint – hit B key to get your screen completely black. Hit B again to go back to your presentation.