I'm a firm believer that if a tech issue with your slideshow presentation derails your message, you don't know your material well enough to deliver. In fact, I very rarely use slides to present material. The only exception is if it's a Masterclass and I'm the only speaker.
True confidence doesn't come from splashy presentations and cool-looking animations. It doesn't come from fancy clothes or even a new haircut. It comes from truly knowing yourself and the message you want to convey.
I learned this lesson early in my days as a theatre kid in high school. Before every live performance, my teacher would tell us the same joke:
An actor got their big break with one line in a play: Hark, I hear a cannon. Now there are no small roles, only small actors. This particular actor wanted to do the best work with this one line.
They practiced until it felt natural. They researched cannons so they could connect with the reality of what it's like to "Hark! I hear a cannon!"
The day of the performance, they rehearsed that line on the walk to the theatre.
"Hark, I hear a cannon... Hark! I hear a CANNON!"
Finally, the moment arrived. The theatre was packed. The house lights were down. The play was in full swing when the actor stepped onto stage in the spotlight and proclaimed "What the hell was that noise?"
The moral of the story is, it doesn't matter how much prep you put into your material. If you don't understand the broader context of what you're saying, you're going to flub your line.
Confidence comes from knowing the broader context of what you're sharing. It comes from prioritizing what the audience needs to hear in that moment. And it comes from just being aware of what's going on around you.
In my media coaching, I tell clients to hold on to one central idea, instead of memorizing a script. It's easy for your brain to hold one idea, which means you can be open to other things around you. You can pivot and shift as needed.