I wanted to somehow give it some depth. Notice the two on the bottom. They are done in a diamond shaped spiral. Now see the two on the top. They are done in a wide V shape echo. Since I am no expert in creating depth, I drew it out on paper many times first to see what directions the lines would look best.
Once I decided on how I wanted to quilt it I did not bother with pre marking. These are relatively small areas that I was quilting quite densly therefore I didn't feel the need to mark it first. I was quite pleased with the outcome.