Help with fabric and arm.

[Audie Eagleheart]

I made some gestures from this reference. then I filled it out with a solid color. I've looked at satin material over the net and noticed they generally only has 3 values. So, I thought this would be easy: sharp folds, sharper, brighter highlights with creases being the darkest. But, I keep screwing up the forms of the folds and those very subtle ones sharp edges but not too bright or dark on the value. I end up making the whole attire look too bright or too dark and saturated. Anyways, thats my palette there and my sketches.