So far the painting process is quite straight forward. The washing of the model is no different.
Here I wash the model with Agrax earthshade. I try to imagine that the light is coming directly above the model. That means that I try to go light with the wash on the top surfaces and heavier at the bottom. Wipe of some of the pools and some on the bigger panels.
I tend to use the wash, not only to bring shade but also texture and striping.