I purchased some new flannel the other day and forgot it was still in my car. Lot of chaos and yes forgot about it. I usually throw everything right into the washer. My machines are always on the ready to sew something. DH said his mother used to keep fabric from fraying by folding the fabric corners down then stitching on the diagonal. Sometimes she would just make a couple whip stitches also throughout the edge of the fabric. Worked for her and worked for me. Still shrunk but didn't fray as much. I always pre-wash.