My third take, based on Amanda Charbonneau’s helpful concept map from Round 6.1. For more advanced vim buffers, see Likit Preeyanon’s screencast here.
Process: Tried to pick a simple topic to focus on the experience of converting a concept map to a quick spoken lesson, but ended up writing bullet points — and rearranging them — more than I expected to try to cover the main points quickly while remaining systematic and coordinating with the visual cues.
Basic vim is not the most visually stimulating topic, but the screencast does make visual changes easier to follow than on a printed page (eg moving between the editor and the command line, or a warning popping up a the bottom of the screen). Animating/highlighting the cursor to emphasize the relevant part of the screen would help.
Edited to add: I have nothing against emacs, just trying to teach what I had experience with 
Here’s a nice concept map introduction to emacs, and a series of emacs introductory screencasts (not from Software Carpentry).
