I try to take a photo of every quilt when it's done. Sometimes they get away from me. I write down info about the quilt, yardage, # of blocks, etc, etc. in a spiral notebook as I work on each quilt. It's never been about posterity, just to keep me sane as I'm working on the quilt. I have hung onto most of the pages, with a few fabric scraps pinned or stapled to them, just in case I ever want to make that design again. But truth be told, I'm not very organized about it. Someday I ought to take time to go through and put them in some kind of order, maybe make a file folder for each quilt and put the folders in small decorative file box. That way I wouldn't have to go hunting through my stacks of papers.