Hi guys, just here to complete what I said in my post at FTW.
First I am sorry about writing badmoons yellow instead of sunburst yellow.
That teqnique is a good one but here I will expand on how to paint space marine shoulder pads:
Spray chaos black, now base with Iyanden darksun, wash repeatedly with sunburst yellow adding more golden yellow each time, run watered down badab black into recesses, now highlight with mithral silver, then boltgun metal then finally cover your highlights with golden yellow. Wash with a heavily watered down mix of iyanden darksun, golden yellow and sunburst yellow. This should leave you with a clean finish.
And now this is how to paint metalic yellow (so when you want a gold colour that is not quite gold): Spray chaos black, now paint normally up to wash badab black into the recesses in the tutorial above. Instead of highlighting drybrush the model with the silvers and gold (makeshure your gold covers your silver) then finish as above.
For quick jobs I just Iyanden then golden yellow or Iyanden then sunburst yellow then golden yellow but above is what I do on models that I want to stand out.