Start with a basecoat of your preferred black. I like Doom Death Black personally!
Run a thick edge highlight with Caliban Green , hitting all edges. Then thin the paint down and glaze a faint green gradient to the extremities and edges.
Second thinner edge highlight with Warpstone Glow , again hitting all edges. At this point you can also draw in cracks to simulate battle damage.
Last point highlight with Moot Green . Focus on sharp points, including any cracks you painted in the last step that meet.
Additionally, bring back your black of choice ( Doom Death Black for me) and embellish your drawn cracks with a dash above the highlight.