If I were doing it, I'd just use my walking foot with the dark clear thread in the needle and whatever thread matches the back in my bobbin. A diamond grid in the middle would compliment the diamonds in the border. I might divide the inner border and sew a few straight parallel lines. For the diamond border I might do a meander or stipple stitch on there. Or super simple would be to outline each diamond to make them stand out. Just doing an all-over meander, loop-de-loop, or stipple would work also.