i've seen bargellos' quilted in many different ways- all are beautiful- some follow the lines, some use swirls, feathers, other fancy quilting---it is not an issue of (how it should be done) it's your choice how you would like it to be done- when i did my granddaughter's 'Ashley's Ocean' I quilted waves & bubbles (for the air bubbles above the fish) for my brother in law's outdoorsy appliqued bargello i quilted trees, deer, wild life on it. I think every quilt deserves it's quilting design to be an individual choice made for that quilt.