There are times when I need a good looking gold letter but the budget doesn't support the real thing. Here's a techniques that will fool most any novice.
Of course curved dimensional letters show gold the best. My favorite underlayment is acrylic yellow and orange artists colors like Liquitex. Mix these colors together to get a rich yellow gold color applying it over a white primer. I like to model these colors so there's a little variation in the lights to dark. This can be done without much care. Don't worry about getting a smooth coat. Just slop these colors on. Once dry come back with Modern Masters Irrediscent #194 gold.
This is a latex paint that doesn't have good covering power. And that's to your advantage. With a soft brush apply a thin coat and your done. No need to pile it on. That will hide the underlayment. It's almost like magic. You'll laugh at how easy it is.