Contrast is the most important thing in NMM technique.
This technique is intended for using mainly on tabletop quality figures, but with more layers (I used just 7-8 here, including base color and a wash) it can look quite well even on display miniatures.
I will show my technique on terminator librarian shoulder pad. It is hard for me to give precise proportions, as I use mostly my intuition while mixing the colors.
NMM gold – JerzyK’s way
I start with base color (pic. 1) by mixing yellow with little brown and blue, ending in dirty yellow – it is just the way it should be 😉
Then I make wash color by adding more brown to the mix and diluting it to dirty water consistency and apply it to the surface (pic. 2) – it helps to mark various hollows on the surface, which are afterwards emphasized with more precise application of another layer, which is basically wash color with addition of a little black.
The next step is cleaning everyting a little bit with basic color (pic. 3) – washes can sometimes leave messy areas.
I add a little white and blue to the basic color and focus on areas which would collect more light (pic. 4).
From this step I will be creating more and more contrast, which is the most important thing in NMM technique. Another layer of lighter color (more white and blue) is applied within the limits of the first highlight (pic. 5).
Finaly I use almost white highlight with pure white blicks on highest places (pic. 6).
Sometimes before the last step (white and almost-white highlights) I apply blue or green strongly diluted layer if overall color is too yellow.
You can easily evolve my techniqe to get better results, but even now with just a few layers and little time you can achieve effect which look well on gaming miniatures (pic. 7).
And here is another example of a miniature painted in a similar way: