Since you've already quilted this you have no choice but to use a traditional type binding. I would suggest bias vs straight of grain though since you're doing both inside/outside points. I did a star table topper last year and 'birthed' it. Sewed backing to top, left a hole for turning. Got all those points poked out and then did a seam all the way around the outside edge (1/8 - 1/4" from edge). Then I did minimal 'quilting'. Actually just did decorative stitching over all the seams and called it good as it's a) small and b) not likely to be laundered often.