As always- How far apart does you batting require. The farther apart the batting suggest the less quilting I would do. Often less is more! I use invisible thread on top for my stitch in the ditch and a coordinating thread on the back. Remember if you use a dark thread on the bottom then there maybe "dots" that show up on the white. I would use variegated thread on the bottom.
I would start on the outside of the large center points, then circle edges, last the outer star points. I like the octagon basting around the star. use blue painter tape to make straight lines!
Good luck and have fun!!!!!!!!!!!!!