The general answer as far as gold is concerned is the same as for any metallic look. First, you have to determine whether you want a glossy or lustrous look (polished or matte finish on the metal).
Any reflective surface has its own color (unless it's a real mirror, such as chrome), but reflects ambient light and shadows with greater or lesser degrees of contrast and sharp-edged highlights. A low-luster finish has soft-edged highlights and shadows, while on a polished surface has they are sharply defined. Observation of different metal objects in various lights will teach you the "look" of different types.
You'll almost always have to use various black/white or light/dark gradients in overlay or multiply mode, and satin effects often help. Pick a base color that's close to the kind of gold you want to emulate, then use gradients and satin over them. Don't limit yourself to the Effects panel. You can do things with clipped layers that you can't with effects. Experiment.
There is one technique I learned from Bert Monroy, the absolute master of Photoshop textures, that doesn't involve using a gradient (and, as you've found, Photoshop's default "metallic" gradients are more or less useless). With a slight variation, it works for most any metal. Bert's video on this is here on revision3.com, so I'll not repeat any of his steps. Although this demo involves text, it works for any object.
I prefer to use a live Curves adjustment layer with a Hue/Saturation layer set to "Colorize" above that. This variation lets you play with the highlighting and tweak the color after the fact, should the overall design require it.
Here's what this setting looks like:
By playing with the Curves layer, you can move the lights and darks anywhere you need them, and make them soft or hard to taste.
