just find a gold paint that stands out, dont limit yourself to just
GW paint.
unless your painting for a competition, you dont need several layers of highlight to make a desent model on the table.
this one i basecoated the gold whit airbrush, applyed a shade and repainted the raised areas whit a brush using the same gold as i basecoated it with.
the natural or artificial light combined whit the shade wash creates the highlights.
i used mystic gold from green stuff world and tamiya black panel line as the shadewash.
nothing else.