If you need to fiddle with it to get it all lined up before stitching down, I'd use Elmers SCHOOL Glue...the school glue is actually a thick starch and will wash out easily. But, meanwhile, you can adjust and press with your fingers until you have it just right.Then iron it down, using a piece of parchment so your iron doesn't get sticky and proceed to stitch it tightly. Every quilt gives us it's own lessons!