In addition to plotting my latest WIP on sticky notes, I sat down and wrote a character sketch for each and every character, before I started the page 1 re-write. It's a technique I've not employed in the past, and wanted to do this time, so I would have consistent character motivations.
Even for my secondary and tertiary characters, I worked out motivations for actions in advance of writing. I did it in the form of short stories that dealt primarily with the main conundrum I wanted them to confront in the novel, or the way they fit into the overall plot.
Only a few turned into genuine short stories. I used none of the material from the character sketches in the novel, but I had it available for reference. I didn't want the writing of the novel to get bogged down in questions of, "Why is s/he doing this? Why now?"