My simple answer is depth. I've been in love with creating layered fiber art quilts for years. My art has changed in that time from some simple layering of a few fibers, to a more complex layering using many fibers to create an almost fuzzy composition until it is quilted. Using these different fibers has allowed me to make the illusion of depth with the more dissipated fibers blending and disappearing into the background and the more detailed solid fibers behaving as if they are close to me. My chosen base fabric also plays a factor. I prefer batik or batik like fabrics that are a bit blurred. And yes, the way I choose to quilt it helps to create an organic movement. Think of the wind gently ruffling the flowers and leaves.
It's really not rocket science. I just love to play.