At first this might sound trivial - you push the B button on the keyboard (or the black screen button on the remote) and the screen goes to black. you push it again and it returns to the picture you had.
It's not trivial. This tip has a lot to do with your presentation credibility.
Take charge of your PowerPoint presentation
You can easily spot a presenter who is a slave to their PowerPoint. Once they start the first slide, they can't stop. They keep going, slide after slide, until the end. During that time there is always a slide showing, regardless of what is being said or discussed. It's wall-to-wall PowerPoint.
Eliminate split attention
Here's the real problem. Suppose you're showing a picture of the new company truck, but your speech or discussion strays onto company cashflow - which means that the picture is now almost or completely irrelevant. So where is the audience supposed to focus? On you? On the screen? That's split attention. Only one thing is certain: the ambiguity will cause an outbreak of glazed eye-itis. What they really want is for you to be so tuned into them, that you wouldn't dream of distracting their attention with irrelevant visual material.
Use PowerPoint as a servant
The solution is so easy. Do yourself and your audience a big favour - push that B button and allow the audience to turn its focus exclusively on you. Then, when a slide becomes relevant, push the B button again and move on. Right away your audiences will decide that the PowerPoint is your servant, not your master.
Enjoy the boost in your presentation credibility.
Want to get even more mastery? See PowerPoint Tip 10.