I just throw my fabrics in with my regular laundry, lights or darks, with a color catcher sheet. My quilts are made to be used so I wash the fabric the same way I would wash a quilt. If it bleeds, I throw it away. I don't do a separate special wash unless I'm doing large amounts of yardage at the same time for backs. This way I always have all the fabric washed in stash and ready for inspiration to hit.
Diana