Here's a technique I just invented. If you have a long drive or walk, you can plan out a lecture or a paper in your head. First think of 3-5 major topics. For each one, think of 3-5 sub-topics. Now you have 9-25 ideas. When you get to your destination, you can just jot them down. You might not remember all of them, but that's fine.
For example, on my walk today, I developed part of a lecture on improvisation for my jazz course.
I. Relation between composer / song and improviser.
The compositon does matter / favorite structures / the idea of "standards"
Jazz a performer's art / zero degree of improvisation can still jazz-like
III. Types of improvisation.
embellishment or ornamentation / paraphrase / blowing over the changes / licks and clichés / "free jazz"
IV. Structure of a solo
Telling a story / Beginnings / endings / development and climax / compare contrast with classical styles
V. Examples of improvisers
Stan Getz / drum applications: Max Roach / Art Tatum and the ornamental style
I didn't come up with 5 subcategories in each major division, or else can't remember them, but I essentially organized my ideas. Each subtheme, then, would be something that could be explained fairly briefly. I started in on my ideas about rhythm too, but then I arrived back at home.