Wow, you and I have the same methodology, I think. I have a bullet list in my head of the talking points I want to hit, or the key phrases I want to use. Then I just stitch together a store live, in front of the audience, that links these bullet points together into a single, cohesive narrative. That way I don't get wound up about remembering the exact wording of a paragraph of text, or whatever. I know what I want to say. I can see if the audience is glazing over, or if they are engaged. And I adapt my story as I go along, and get a feeling for how the audience is receiving it, and how quickly I am getting through my points. Sounds similar to your process? when I have my presentation's core arguments / structure nailed down, I can just explain / improvize what I want to tell around it