Base in   Iron Hands Steel  : 
airbrush lighter silvers to build brightness.   Ironbreaker    Runefang Steel  
Airbrush   Mortarion Green  (CLEAR) into the deepest recesses. This will become almost black under the red layerIt's important that the shading is tidy before the red goes on, as splashes of either the green or blue will look quite messy after. It's worth taking the time to get it right