I'm SO sorry for what I am about to say, but thank you for showing me how nice my sewing stash is ! You have such a big job ahead of you. I would sort by fabric content: cotton etc. Then I would sort by color. Empty several of the containers and put the fabric in them by color if they are cotton. I am wondering if you do all this work, will your grandmother maintain it ? I hate to see you do this work and then in a year, it looks just like it did this year. My own mother was not a cleaner/neat person and I am exactly the opposite. Each year when I visited her, I would work the whole time cleaning and getting rid of junk and come back the next year and all this new stuff would be there. She just wasn't into cleaning and having a neat house. Maybe Grandma is like my Mom ? Good Luck.