the batting you choose will tell you the maximum distance your quilting lines can be.
Warm and natural will allow quilting at a distance of 10". Looks like your blocks finished at 8"? I would just quilt around the blocks, quilt around the center square patch of each block that is set on point. The green square on the bottom block, the black square in the center block and the black and green square-in-square patch in the top block. Then I would stipple the border.