Currently, it goes like this. A base coat with light camouflage gray. Then a raw umber wash, then, after drying, I use Vallejo Iraqi Sand and paint in the grain. Then a wash with panzer grey, then I use three shades of blue and more or less copy the blue paint that is on the real building. Then I give it a wash of acrylic light blue, removing most of it by blotting, not wiping. Then I take a piece of sponge, with some Iraqi Sand, blot the sponge on a soft cloth until just tiny dots appear when touched to the model. The final step is a very dark grey thinned with water about 50-50 and a very fine bruse, (000), to line in the lat boards and other other raised details.