So, as part of my just-in-time scene planning, my test process for now involves writing out the scene card for the scene I am about to write, as well as the next one, and only that far in the future.
My scene cards include the major story point that the scene must convey, the plot point and the emotional impact on the main character, as well as the setting and a list of all the characters that appear.
Since I am not plotting the whole thing out in advance, that means that I need to develop the minor characters and scenes when they first appear. While this could end up slowing down my writing process later, at least at this point, it seems to be effective. Because I know what scene and what context the characters and setting will first appear in, I know what emotional tone and impact they need to have for the PoV character in that scene.
Today, after going back to review all of my metadata, including my blurb, theme, and central concept, as well as my hero’s profile, I started describing the minor character that she interacts with in the first scene. I think I have enough detail on him now, so tomorrow, my task will be creating the setting.