Those cheap clip on lights have pretty good reflectors. Because they are aluminum they start out with the advantages of aluminum - the best wide spectrum reflective material known, as far as I know. They are pretty shiny too - another advantage. And, they have ribs around the circumference, which makes them diffuse the reflected light quite a bit. I would just use them as they are, as I now do. And, my PAR measurements were good, almost what I expected, based on the data in the sticky in the lighting forum.