The scrap quilt I make for the kids has sashing and cornerstones. The blocks are 6 3/4th so I cut a sashing fabric strip 6 3/4ths across the width of the fabric and then cut 1 1/2 inch strips for the side sashing. I cut 6 3/4ths strips and a cornerstone fabric 1 1/5 wof. I sew the two strips together and then cut my sashing strips 1 1/5 from the strip set. That way all the sashings are cut on the length of the fabric and are more stable.