Step 0: Prime Black
Step 1: Base coat with Steel Legion Drab (SLD)
Step 2: Shade panels with Zandri Dust (ZD). Make sure to leave SLD showing in places.
Step 3: Shade panels with Screaming Skull (SS). When shading make sure that as many dark edges meet light edges.
Step 4: Mix a weathering powder wash using Secret Weapon Miniatures Green Earth Pigment (GEP). Add enough thinner to the water/powder mixture that surface tension is broken so the pigment flows easily.
The last step is to neatly edge the bases using Steel Legion Drab.