For me I let the quilt speak to me......I know this sounds strange but I look at many places such as magazines, on here, books and website for how others have quilted their quilts and in the end I study the quilt and the fabrics used and if its a customer quilt get the story behind it (who its for, what inspired the making and fabric choices, where its going to be used) and in the end use all of these factors into how I quilt the quilt. Also look at the designs within the fabrics used many times these are great ways to quilt and add to the quilt and not take away from it. I hope this helps as its kind of hard to explain at times how I come up with designs or once I start a project the next idea just comes to me.