I first browse thru my pinterest boards that have fmq designs l saved there. Or my quilting design books. Then, l audition several ideas by placing a sheet of clear plastic ( like sold to protect table cloths) over the quilt top and drawing on the plastic with erasable markers. I take a photo before erasing. I compare the photos l took of various ideas, & select favorite. Be sure to outline the plastic with blue painters' tape so as not to accidentally marking the actual quilt.