I'd try out various quilting designs I might want to make on the sashings using a Preview Paper [Golden Threads] or clear vinyl marking with an erasable pen. Straight lines do work but you might prefer wavy lines or something else to your taste. The quilt I did that was similar to yours I outlined the parts of the material print so that there wasn't a fist sized area not quilted. I put in clouds in the sky and grass on the grass, etc. I loved how it came out. Unfortunately I gave it away without taking pictures.