I'm not sure how they would respond to your light array, but the first step I'd recommend to advance from where you are now is to play with specular highlights. Human skin looks fairly flat straight on to a light source, but is quite shiney when the angle is oblique. Examining photographs, and, say, the skin of your own arm held up toward a light, should provide a reasonable guide to the size and level of specular highlight to aim for. When combined with a good bump map, this can be a great aid to realism.