Now, this step might scare some of less experienced miniature painters, due to inclusion of terrifying NMM technique (despite it being just a sloppy layering in this exact case).
That's why it's completely optional. If you want to replicate my process, but avoid complex techniques, here's couple of alternatives:
- (airbrush) Basecoat with black, and then give a slight spray of light grey
- (brush) Basecoat with black, and then edge highlight with grey > light grey > white
You can even combine these steps: basecoat with black, then spray with light grey, then edge highlight with white. This was the exact thing I did with the newer Combined Army Remotes couple of years later.