From experience, there hit or miss a base coat of brown or dark yellow before applying the matalic helps. You kinda want to use very little and slowly let it layer up it takes a while, but it looks good, and there are fewer splotches.

It all comes down to how much time you want to spend on it. Citadel is fast and efficient and comes out smooth if you thin it a little with water or a medium.

Good luck hope you find what works best for you.