[caseorganic]

I always start in my head with the goal of the speech, then I sit down and make a quick outline.

I use the outline as a skeletal structure for my slide deck, otherwise I spend hours tweaking font size on the slides instead of understanding the overall goal of the talk. Once the outline is done, I add in a bit of muscle to the talk - one to two sentences per point to the outline. Then I go to the slides and add full-pages images for each slide, with short topic headlines for each part of the talk. Then I memorize the gist of the outline sentences and embed those mentally into the slides (making the slide deck a memory palace). When I get up on stage, the slides remind me of the storyline or topic I'm on, and I simply tell the story.

I have written out some talks before, but I only use that method to practice the talk as if I were speaking it out loud. I write with the same tone of voice that I speak in, and write it to get it out of my system. I don't look back to the write-up afterwards.