Pick a color you like.
Basecoat slightly darker. Layer with the color. Wash with Talent-in-a-Bottle (Agrax Earthshade, liquid gold for people who can't paint like me). Drybrush with the layer color. Drybrush lighter with a slightly brighter color. Optionally edge-highlight with the same color as the second drybrush.
About 80% of the model's done right there, no need for finnicky finger-cramping fine-painting, and It'll look more than good enough for the tabletop. I should know.
Do the same to the gun, and you're basically done aside from optional details.