Thanks Bryan. The effects are achieved via air brushing and oil dots and washes. I like to use Model Masters enamel paints. I've used these for years and that's what I'm familiar with. I'm sure you could also use acrylics the same way. Just seal between coats.
I first apply a flat black primer coat. Then I pre-shadowed with light gray #1732. The base coat Africa Dunkel Grau'42 #2103 was then srayed lightly over the primer coats. Once dry I sprayed Future acrylic floor wax over entire model. This seals everything and supplies a smooth shiny finish for decals. decals are applied and once cured another coat of Future follows.
The future is also beneficial for my washes as they flow better and If I want to remove an unwanted stain somewhere. They can easily be cleaned up. I use Winsor & Newton Burnt Umber mixed with Turpenoid. I allow this to flow into and around details depressions and around rivets. To remove unwanted wash just dip a clean brush into some Turenoid and wipe away. Rust effects can be created with washes of Burnt Sienna, yellow ochre cadium orange.
Sometimes I'll use this Burnt Umber to alter the shade of the paint on the lower surfaces of the model near the ground as dirt and grime have accumulated. I guess this is what people refer to as a filter. Allow all to dry.
After the wash I'll take oil soft mixing white and mix it with my base color to lighten. Then I'll add this mix with sporadic dots. I'll also use yellow ochre and a little burnt umber. One dot at a time I'll take a clean brush dampen it with Turpenoid and work the color in. Sort of blend it together.
Once happy I start my dry-brushing. Soft mixing white oil paint mixed with my base coat. Dry brush all raised surface detail. Once dry I'll add more soft mixing with to my original mix. I want to add layers of lightning effects. I'll dry brush once again. This time use a softer touch. I'll do the same thing with tires. It provides grey highlights.
I want to add that you must wait for all the steps to properly dry before you rush on the the next step.
I'll then use some earth tone Alphacolor soft pastels for pigments. Just scrape the colors you want with a razor blade into a fine pile. Then brush on and use a Q-tip to work the color in.
Once I'm happy with my results I'll seal everything with Dullcoat.
Hope I haven't forgotten anything, Hopefully this will be helpful.