I wouldn't call it a 'technique' per se, but I've made this exercise twice and is so much fun...

I sketched all values with semi-random colors. The idea behind it is to practice value sketching regardless of chroma/hue.
I tried keeping to something close to a logic - the face temperature zones were somewhat respected - but I was mostly trying to make sure the shapes were easily recognizable and somewhat being affected by a single light source.

The first time I tried this approach was right after getting my first airbrush, a few months ago. I started from a botched attempt at a zenithal highlight, with paint streaks and spiderwebbing:



From there I started sketching lights on the face:



I moved to the rest of the body and the end result was this:


I tried using glazes with the airbrush and mimic Trent Denison's 'sketch and refine' approach, but i chose a wrong color (too light, too much white in it, therefore too opaque), i was still struggling with distance/paint dilution and pressure and my trigger control was terrible, so I just covered everything:


Well, to simple green and let's try again!
some week later I stripped the paint and re-primed, this time doing the zenithal well enough:


Again I started from the face and moved on to the other areas, but this time I wanted to go for a warm scheme, in contrast to the cooler one I had tried before:




I think the end result was better, the volumes are better represented and the scheme seems more cohesive.
I, of course, tried doing the same thing with the airbrush, now a bit more knowledgeable with the tool. The end result was subpar, but still better than last time:


The high value areas are nice enough, but i'm still missing some midtones. Well, next time it'll be slightly better!

this is really interesting, i think that i will try myself at this exercise as soon as i will have received an anatomical bust i ordered some days ago