I am not a fan of Powerpoint. But mainly because it's used very badly. There's a ton of things on the screen, all distracting and pulling the attention of the audience away from your message.
I'm not going to go into that right now. Quietly simply, I want to speak to you briefly about the colour of your slides.
Yes, really that simple. The trouble is that Powerpoint slides that are white background with black writing like this. It is IMPOSSIBLE for the eye to ignore that bright white light. And it's IMPOSSIBLE to get the audience to focus on you while the eye is being constantly drawn away by the bright white of your slides. You will not win in a tug of water between bright colours and a nicely dressed human being.
Imagine for a second, you are watching a presentation, but the presenter is standing in front of a television screen that's showing a news broadcast. How hard would it be to focus on the presenter?
So, my advice is that you use a black background with white text, as this is focusing without pulling focus away from you.
I advise you that you use this for all of your slides where possible. It's clear enough to allow your audience to focus on the message of your powerpoint slides, but it will prevent them from getting distracted by the bright white light when they should be listening to your points.
It's also a little bit more soothing and if you giving a presentation in a darkened space, it cuts down the amount of horrid jarring bright light.
Try it on your next presentation, simple slides with black background and white text. Give it a go and let me know how it goes.