Beautiful floral ... busy. I would sash around each side of the block, either in white or light pink to match the pattern and a sashing post of black on each corner. You want to draw the eye of the viewer to the print, not away from it. Use fabric of same texture or close to it for the white/light pink sashing and black sashing posts. I would stay away from shiny fabric for sashing/posts. For the backing I would not use white but a light color, possibly pink - something pleasing to the eye.