I'm working on a sequel right now, and of course, I've written other manuscripts between the first book and this sequel. That means I'm doing a lot of going back and looking things up. Yes, it's a time suck.
So, I decided I was going to keep track of each character and what they look like. Each class period and time of day it occurs. And any other detail that I might need to know later. I'm making a list of these things at the top of my planning document, and I have it open next to my actual manuscript. Aside from the time it took to create this cheat sheet, it's really saving me a lot of trouble. And I've learned a valuable lesson: create a cheat sheet when I start a new manuscript, even if I don't plan to write a sequel (which was the case with this story).
How do you keep track of all the info from one manuscript to the next or even within the same manuscript? Do you have a cheat sheet?