I've reached a complicated chapter in my novel in which I need the geographical features, proposed plans and timeline to be correct. I read the relevant parts of five historical non-fiction books and made notes, but I still didn't have a clear picture in my head. So, after considerable thought, I wrote chapter headings and typed up the relevant information under each titl3. Next I made a list of things my protagonists would do, and their reactions to events as they occurred in sequence, in each chapter and finished by typing up a few quotes from historical personages.
For the last three days I've been working on Chapter Thirty-One. Thanks to my notes everything, as the saying goes, has fallen into place.