Fucking up
At some point or another, the probability of fucking up in front of a lot of strangers you don’t know approaches one. It’s going to happen. You’re going to say something you didn’t mean. You’re going to blankly stare at your screen when you forget the argument that you’ve never, ever had problems remembering before. You’re going to accidentally horribly insult someone, and it was the last possible thing you meant to do. These things happen.
People don’t care
I’m sure you recognize this by now. Most people in life don’t care about you or what you have to say. This goes tenfold for a conference. Most attendees will be bored and will likely be on their laptop anyway. It’s a harsh world.
That’s cool. That’s the number one comfort you can usually rely on. Even if you find something you said to be glaringly horrifying, chances are it’s not that big of a deal to them. Again, this is obvious, but it bears repeating: you’re probably going to be fine.
The best thing you can do is not draw attention to your gaffe and just move on. I’ve certainly found myself in the middle of stories that were irrelevant, too long, and boring as rocks. Sometimes it’s best to cut your losses and say “and wow, this story is stupid, boy am I sorry” and move on.
Stay humble
As with most things when you’re on stage, staying humble is a good quality to have. You’re pretty exposed, and if you mess up, well, just be honest. If something obvious happened that you can’t sweep under the rug easily, put your hat in your hand and say “wow, I did not mean to say that… sorry!” or “crap, totally blew my train of thought- let’s circle back on that”.
Have an out
A good approach is to always have an out so you minimize the chance of mistakes. Practicing your talk over and over is great, but it’s also a good idea to be strategic, when you can. Usually I try to do a minute or two at the start of my talks and improv a small joke or tell a funny 30 second story, just to get people interested. If I’m really nervous about losing my place, that’s why I have presenter’s notes. Or notecards. Or even slides. There’s no reason you can’t use all these things to your advantage to make it less likely you’ll mess up.