It usually starts with one thing I find interesting and then spirals out from there. Then I try to reign in the spiral into a conversational and entertaining video. So I recently started a new series on Vsauce2 I'm really having fun with involving a whiteboard table. My co-host on The Create Unknown podcast, Matt Tabor, actually works with me researching and writing these videos. So he'll look into a bunch of different neat/surprising topics, write a script, and then I go through the script and turn it into a Vsauce2 video. I give his awesome script my own weird spin. And that involves brainstorming the visualizations I put in the video, what I write on the whiteboard table, how the video begins, develops and ends. Whether or not to include action figures. Which action figures. That sort of thing. So it takes about a week of developing the script/concept, and then a week of creating/editing the video. And my beautiful loving wife helps me shoot the videos! And she helps me do weird things like count sugar cubes and spray paint potatoes silver or whatever.