The only thing I'd suggest, is that washing models adds a ton of depth with very little effort. These guys here are primed white, given one or two layers of base coat, then washed with an appropriately darker colour...
For example, the leather is "Snakebite Leather" with "Agrax Earthshade" over it. The Metal is "Mithril Silver" with "Nuln Oil". The green is Lorean Green with Something Camoshade. The black is Mechanicus Grey [?] with Nuln Oil over top. The hair is
GW Yellow Base Paint with a wash of thinned Snakebite Leather.
The white is white primer, given a very pale-blue custom wash, and then drybrushed white again. Skin is Elf Flesh with a mix of Elf Flesh and Reikland Fleshshade washed over it. Look at the Ear of the right guy to see the best contrast.
That's it. Just washes over base colour to get this effect. Wash over the whole area. If it gets too dark, you can always do a quick drybrush to lighten them up.
By working over a white primer, with thinned paint, you get natural highlights on raised surfaces, and then adding the wash gives you shadows and a richer "mid-tone".