It takes time to create a good presentation outline. For me it takes one or two days, depending on the complexity and length. How to get from an idea to the first draft you can perform? In an organized way.
Step 1: Pen and paper
I use old style pen and paper method for the first draft. It allows to add items, cross them out, add small drawings in a non-linear way. I do not hesitate to return to a previous points if I realize that there is something to add. Removing takes place later.
Step 2: What will your structure be?
Think about the structure type you’d like to use. It can be the traditional introduction-3 arguments-summary one, but even better if you can wrap it up in a story. Problem-ideas-solution often works fine. If it applies to your subject, you can also show a story of your product usage and explore how to use it to solve user’s problem.
Step 3: Main points
Then write down the main points. What do you want to say in the introduction? What are your main arguments? What are sub-arguments? I leave spaces around the arguments or big events in the story.
Step 4: Examples and sub-stories
In the empty spaces I add examples, explications and sub-stories.
Step 5: Balance
After completing the first complete version it is time to look and see if the main points have equal weight. If you have examples, make sure that there is one example per point. Make also sure that it will take similar time to cover each of the examples.
What do do if you have much more content in one point? You can either decide to keep it if you think it’s essential, move content to other points, remove examples or split the big point into smaller, more detailed ones.
Step 6: Slide set
When I have the paper version ready I move to creating the first slide set. Usually each main point and each example will use one or two slides. You can start with the titles only and then add content (images, diagrams, text) you see fit.