It just looks like simple layers with a few glazes to dull down the main parts.
I do t use the new range of GW paints but I would look to base with a yellow brown colour.
Apply a mid tone gold all over the gold area. Now lighten the gold with adding silver to the mix and apply on the raised areas only. Use pure silver to the very extremes.
Now use a thin brown paint and apply thin coats and glazes to the middle of each strip of gold so the outside edges and highlighted only.
Continue to darken as you wish.
Add a tip of black into the deepest areas.
That's a basic run through, there are many more things you can do like adding green glazes to make the gold look older / weathered.
Or if your feeling adventurous then try this from my blog.
http://mallysminiatures.blogspot.co.uk/ ... -gold.html