Trace cookie cutter for shape, work in negative space around shape after stitching tiny guideline of shape. Use a thread conditioner, Thread Heaven, on embroidery floss to prevent fraying; French knots or stab stitches used for effect.
Cross stich rose mural from wunderschön-gemacht: vintage teatime. Do this with wall paint or with washi tape. Maybe not a rose (and I don't know what washi tape is, but This would be cool wall decoration.