My method for painting the gold armour of my small Custode Kill Team. Use an airbrush for best results.
Basecoat with a 1:1 mix of Vallejo Metal Color Gold and Copper
Do another coat with a 2:1 mix of Vallejo Metal Color Gold and Copper . This time paint areas where the light would hit. This is best achieved by airbrushing downwards at a 45 degree angle, as a zenithal highlight.
Paint an even smaller area of pure Vallejo Metal Color Gold . If you are using an airbrush, do this as a straight down zenithal highlight.
Cover all of the armor in a wash of Reikland Fleshshade .
Drybrush the armour with Liberator Gold . Try to oly hit areas where the light would hit. The idea is to bring the gold colour of the armour back, so you could layer or glaze the paint with a brush if preferred.
In particularly deep recesses, I like to selectively add in some Agrax Earthshade and Lahmian Medium mixed 1:1. This helps add more contrast.
With a 1:1 mix of Liberator Gold and Stormhost Silver , edge highlight all of the armor that was hit with the drybrush.
Finally do selective edge highlighting of the more prominent areas with pure Stormhost Silver . I would recommend dot highlights of the same colour be put in where applicable too.