I also write info on the selvedges with any handy sharpies
Sometimes I will write on a scrap of paper or I have packages of tags for like yard sales and will pin those. I use brass safety pins for that, or just pin the selvedge.
I made some good scores in my Goodwill rounds today, enough of a beach themed Alexander Henry print for a quilt back -- just when I had decided on a beach themed top earlier this morning!
There were more things that tempted me and none of what I got was on sale, but still several pieces of usable yardage and a piece to my Pfaltzgraff Yorktowne dishes that I didn't already have.