my advice which I give all my students is if you can't see the decorative quilting then do something simple to stitch the layers together. You could do in the ditch or better 1/4" out from the seam in the busy prints and do the more decorative in the lighter areas where you can see it. There are some nice triangular stentils that might work in the corners of the lighter sections. It also appears your thread basting might not be tight enough. The layers appear to be too loose.