The story is complete, so now I'm teasing the detailed synopsis into a script with thumbnails, and then into rough layout pages where I figure out the action from panel to panel.
Apart from close ups, each panel means answering a bunch of questions. Is it an establishing shot? How much of the environment do I need to show? Does the story make sense from panel to panel? Am I introducing a new character here? Can we see his face at this camera angle? Who's talking, in what order, and how much? (Even the dialogue balloons need to be thought out, so that I can place the characters the right way in a scene and with enough space around them for their speech.)
I use very simple models and mannequins in Maya to figure out the perspective and composition of the trickier panels. This lets me play around with camera views, and highlights problems I might not have considered (for example, thick stone walls mean you will have deep windows!). The more problems I solve at this early stage, the better.
Here's an example scene: three riders on horses, and a fourth character standing nearby. I have poseable 3D mannequins, but at this early stage, I don't bother posing them yet.
(Oh, and transparency allows me to see inside the buildings, too!)
