I favour the approach you've just outlined, Gary, that is; one of working from light to dark. Until now, I've been mainly concerned with finding primers that do what they're supposed to. Tick. Then, I've been finding ways to lay on topcoats from a rattle can (Tamiya mostly) by using home made paper stencils to help create Camo patterns..tick.. and then to mask areas off that don't need painting. Tick. At this time of year..and not having a heated workspace (shed is too cold), it takes too long to set the airbrush up. Cross. At the same time, it doesn't like cold weather.
This, by the way, is my compressor:

- Current compressor and airbrush..
Midwinter in the Highlands, is not ideal for painting in any medium, but the airbrush suffers most. I can do a couple of (warmed) fast sweeps with a Tamiya rattle can in my porch, with the windows open and a mask to prevent my lungs from being coated with Dunkelgelb...

. Even then, it's not easy. I really need to be able to use the Airbrush for finer detail, not rattle cans, but that will have to wait until the Spring...
Meantime, I'm doing the sensible thing, and finding out as much as i can...
"Get your facts first, and then you can distort them as much as you please"- Mark Twain.