I only sew with washable fabrics. Every piece of fabric that comes home with me gets placed near the serger immediately. The cut edges are usually serged or zig-zagged that day, and the fabric is added to the correct laundry pile. If it's in the Red color family or if I think the color might run, the fabric gets washed and dried by itself at least once or twice. Multiple runs through the washer and dryer are also indicated if I think the fabric will shrink (cotton) or shed (linen).
Some times this laundering will change the character of the fabric. If I'm sure that I don't like its new attributes, I can put it in the donate box.
After all this laundering, the fabric can find its rightful place among the stash. I really cleaned out my stash this last year. I knew that the very few pieces that did not have the raw edges finished off had not been washed yet, so they were advanced through my process accordingly.
Now my fabrics are stored in boxes (mostly cardboard) and marked by type. My types are: home dec, cotton/linen, rayon/poly/silk, knits, and fabrics to make garments for specific people (DH, and DS).
maer