Cheers for the feedback, everyone! Excellent food for thought!
Regarding the mummies, I think I'll be leaving them like that for now -- I do think they have enough contrast going on, and the slightly brownish bandaged seem rather appropriate to me -- incidentally, here's a proper picture of them:
As for the Fimir, you guys raise some excellent points. Regarding the question of drybrushing vs. layering, I would say that drybrushing wouldn't really have worked on an organic shape with a very smooth surface, like the Fimir's skin, so I was always clear that I would need to layer/paint the highlights rather than brushing them on. That being said, in hindsight, I got too greedy for a quick recipe, which is why the model looks pretty rough -- what I should have done, as suggested by Maurice and Thor-In, is to make the highlighting smoother, via going back in with the original green colour before adding the final highlight on top. Plus I think I'll be using a different wash next time around (dark green vs. brown/green). There's also the fact that the Fimir models are arguably my least favourites from the entire set, though: While the concept itself is cool, the sculpt seems a bit awkward in places.
That being said, there are also a few parts I am pretty happy with: The golden armour works pretty well, as does the obsidian-style axe, if you ask me. And I think I've actually done a pretty good job on the red jewel that adorns the belly plate. Here are some better pictures of the Fimir, too (although they do a fairly good job of making the model look nice, the skin is still kinda rough -- better luck next time
).
And here's a look of the finished undead army, so to speak, commanded by the Witch Lord:
As always, let me know what you think!