The gold on the belt and on his left shoulder work okay. The inverted highlighting that people often do for
NMM needs to be applied right. In these two cases it works out alright. Normally the inverted direction of light at low points and dark at high points only happens when you have a concave form. When you have a convex form the highlights for anything should be "normal" ("light parts up, dark parts down"). This goes for
NMM as well as for any other colour. Using
NMM essentially means that you try to replicate more natural rendering of highlights and shadows on a miniature.
The shoulder thingy (brooch, medal?) could be assumed to have concave features as it is so small. Thus the illusion of "highlighting in the wrong direction" (darks up, lights down) works out okay.
On the belt the two bits hanging from the medal (?) could be assumed to cast a shadow and confirm a good part of the dark dome and the dark part on the spike under the "jaw" also works because of implied shadows. What you could try to change if you want would be the exposed part of the skull dome (his right, image left). That part would receive a lot of light and be much lighter than the rest of the skull and a nice nearly white specular highlight would look nice about 2/3 up the dome.
Also some tiny specular highlights on the lower edge of the eye sockets. If you want to try this then don't make then too symmetrical. The actual specular would probably be a light line that moves along the relatively sharp and curved lower edge of the sockets as you move around it because for each position other parts of the edge would bounce back the mirror-like reflection. Also if you made these symmetrical it would imply that the light is somewhere above the miniature exactly between the eyes and you are looking at it from a point of view exactly between the sockets too. Symmetry on something not symmetrical can imply a very rigid set up.
What you did very good is distribute the whole spectrum of light to dark all over these elements while on the eagle in the banner you put the whole spectrum in each strip of the feathers in the wings, and the framing wing/feather, and each individual part. Now the whole inverted lighting/rendering could again work so lets leave that. The extreme rendering of each part can work if the rest of the miniature implies the same lighting situation but in your case the shoulder pads at least imply a very soft light (a sun) while the eagle seems to be made out of golden chrome and lighted by a spotlight through some refracting filter. So as an individual part the eagle could work but as part of this miniature it is in a different lighting situation than all of the rest.
That could work for example if the banner were woven to imply this golden reflection and is not actually supposed to be real gold reflecting real light on the banner. If you want to change the banner eagle then try to think of it as one big piece broken apart into many tiny pieces that are very near each other. Plan your convex and concave parts and with all the little separate parts you still would have a lot of these specular highlight on upwards pointing edges. Again try to not make these too symmetrical.
And remember: All in context of a miniature painted to mimic "reality". Sometimes just painting what you think looks right without actually looking for the exactly true reflections looks better because the values (
http://en.wikipedia.org/wiki/Lightness) on the whole miniature combined may look more pleasing. The values could contrast when you need them for example to make the face pop out of the miniature. For example one could paint the whole face a bit darker on a miniature that has a white armour surrounding the head to get a higher contrast, or one could take care to have the big armour parts in the same value so it doesn't look like a camouflage pattern from a distance. Sometimes the price for the most realistic
NMM can be the value balance on your whole miniature.
It's for you to decide between accuracy versus aesthetics.