I also sort mostly by color. I have a separate area for flannels, homespuns, holiday, juvenile, Asian, and 30's. Any piece 1/2 yd or more gets ruler folded and stacked by color. I do a lot of applique so smaller pieces are in smaller totes that I've labeled by color. I have red, blue, green, yellow, pink/purple, white, black/brown/grey boxes for those small pieces. My stash isn't huge but I have a substantial amount of fabric and like you, people give me fabric when someone dies or they decide they don't want it anymore. I used to think 'how expensive to make a scrappy quilt of only brown or blue, etc..... but now I just have to go to the right stack or box and I'm ready to piece more tops. I don't just go buy fabric.... I always have a quilt in mind..... Good luck with your organizing... it sure makes me happy to see my stash all sorted and ready. You'll love it when you get it done.