I would suggest the "Baptist Fan" design (Bishops Fan from The Stencil Co) or Shells named by some.
It is easy to do with the walking foot. Lots of burying ends of threads but that goes fast especially if you have a Spiral Needle but the other self threading needles or big eye needles work as well. I have done several using this design. I can mark and quilt a 45x60 quilt if about 5 hrs if I stick with the task.