That axe rocks!
Looking forward to see your paint without paintbrush and washes. In fact I normally paint that way.
Prime in black.
Color one layer.
Some zones of the figure a highlight
Varnihs.
Next unit.
I do not have the skill of non metallic metals, but I did an experiment when painting some units of chaos, so I paint them without using metallic paints... Do not planned to much, just take the pencil and start painting. I remember I watch some mangas series because they paint in only two colors, non metallic, and they looks pretty cool. Do you know what I mean? in example: Mazinger Z, cowboy beebop, berserk, etc... just take whatever photogram of metallic armours and you see how they use browns, grays, white and blues in a very simple way.
Here are some pictures of what I get, those mangas non metallic days. Those units are little or non metallic paints on them:




I do not expect to rise your painitng skills with my quick paint examples, just for sharing. Hope it helps.