I agree with Auntpiggylpn - sashing depends on the pattern. If sashing is going to break up a pattern that I want to see in a quilt then I don't do it. If sashing helps to emphasize the blocks then I use it. I don't think there are any hard and fast rules. Each quilt is a work of art and each artist can be creative and make the quilt just the way they want to. Good luck - please post pictures of your quilt - we'd love to see it.