How big are the main stars (without the shadow star)? If your batting will allow you to use a distance far enough to STID around the main star - then I would do that. Then echo stich the shadow star. Meander the background of each. Then a vine, leaf, or feather design in the frame.
If the main star is too big and you have to quilt inside it ... STID your pieces in the star (assume they're diamonds?) to meet in the center of the star - but again - just the main star. Treat the shadow star differently.