Perfecting the Quilting Stitch by Patricia J. Morris 2001 published by the American Quilters Soc. has a 3 page gem on the quilting design and says design is everywhere but especially in the quilt top, and how to design from the piecing or applique. She gives and appendix of 16 refs p 79 - there are a lot of newer books but you can't go too far astray with this one.