Here is the recipe for my golden armor - I saw this technique posted over on the B&C BA forum and tried to improve it a bit. :)
1) Solid black basecoat. Let this dry overnight.
2) Solid layer of Mithril Silver on all raised areas on armor. This layer should be thorough with no black spots sticking through. Let this dry overnight.
3) 8-10 washes of Sepia. I let each layer dry for several hours - this step transforms the silver to gold. Let the final wash dry overnight.
4) Lightly glaze over with wash of Shining Gold (3 part distilled water to gold paint). This step makes the gold sparkle a bit (ala Twilight :P). Let this wash completely dry).
5) One light wash of yellow (I used yellow Wonder Wash). This step really helps to make the gold pop.
6) Black wash in the greaves and recesses for better definition.
7) Finally highlight edges with first Mithril Silver then Chainmail Silver. That's it.
It takes a long time to go through all the steps but it's actually quite an easy technique.