Hm..it's pretty hard to explain. I just..do what works for me. I use quite a few layers..I should tone it down a bit haha. But anyway, I work the headlights just as I work the rest of the car. Lineart on one layer, then base color, darks, lights, details, highlights, and some other misc. layers. And as always, REFERENCE PICS! Some people think that using reference pics is the n00bie way to do it, but I think its the only way to understand how something looks. By reference I mean just any pictures that help you gain an understanding of its form. Hope this helps, and thanks for the compliment =D