I start all miniatures with an airbrushed primer coat of Jo Sonja's Carbon black. Face was then given a top down directional spray with a medium flesh tone. I pre-mix all the flesh transitions beforehand and keep then fresh on a wet palette, about nine shades in total. In this case I went for a generally pale tone using white, burgundy, yellow ochre, paynes grey and black (all Jo Sonja's) with a touch of purple and alazarin crimson added for further tonal changes. This mix was replicated in oils and added as a final layer in thin coats. The Howitzer is Alclad brass sprayed over a gloss black base and shaded/weathered with burnt umber and black oils with the addition of Winsor Emerald oils for the corrosion.
Hope this answers your question.