I started doing this when I was a performing musician and found it was the best way to fix technique, but it is super helpful generally for fixing whatever material you have to present in front of people: presentations, speeches, intro statements, things like that. Set up your phone for video or just audio, do your thing, watch it back, note every time you look or sound insane, fix it, film it over again. It’s based on the heuristic that our critical mechanism is by nature more developed than our creative mechanism, so it is much easier to respond to an existing thing than to conjure something out of nothing inside your mind. I know it is cringe, but avoid at your own social peril.