After drafting a story's sequence with index cards, I spend a lot of time (and tablespace) arranging and rearranging them to test which frames look best next to each other. I then remove as many as I can to declutter the narrative, though there are usually a few survivors who make it simply because I like them too much.
The next step is to look at color and how it moves across the board. Is there a continuous balance, or does it clash anywhere? Can color codify an idea in one frame and push the same feeling in the next frame? The other day I took quick photos of the index cards and brought them into Photoshop to begin testing palettes and how each asset should be illustrated.