At MQS this past May, I bought an arch guide ruler from Linda's Electric Quilters booth to use with my longarm machine. I haven't used it much since then, but this quilt I recently completed had great negative space in the alternate blocks to create a quilting design with the ruler. This is the design I choose for the quilt. On the pieced block on the right, you can see where I drew out the quilting lines with chalk. I like testing out an idea with chalk first before quilting it if at all possible.
I tested both sides of the ruler to decide which would work best with the quilt. I like this design, but felt it left too much area unquilted in the center of the block.