All of my computers always have a generic folder for "research." This is dangerous because the folder gets very full and disorganized. I usually have one research folder for every novel, but during revisions when I do my fact-checking or don't understand my own description (yes, it happens) I have a hard time finding the right files.
Tori from my critique group has pointed out some problems with navigation in the Fashion and Fiends country house. So as I'm removing some minor characters, I'm also fleshing that out. Problem is, I have to make sure the details are consistent with the first book. I remember the layout of the house and the important stuff, but for example:
What does Étienne have for the countertops in the kitchen? Granite seems to popular and easy. Marble is too fancy for a country house. I don't remember.
So I started an "Étienne Household" file and divided it by room. Anything I use will go in that folder to refresh my memory later. I searched to answer the countertop question (and I searched the original manuscript hoping the answer was in there, but I deleted that chapter with the in-depth description). I googled and pondered and found other items I had to use in the house. Just had to. Into the file.
But I thought I'd mention, that the Behr paint company has an online paint center where you can select colors and then "paint" them on the walls to see how they look. You can use four colors at a time.
See www.Behr.com for details.