I got two of my trading balances crashed trading silver so it seems to be the worst pair to me. I avoid trading commodities since then. But Eurotrader offers comparatively narrow trading spread and high leverage that help me earn more on average.
The metal commodity is highly volatile, rush in decision-making could be dragged in the big floating loss, trading on gold if using a tight stop loss will often hit due to high volatility and dynamic of the price movement, however trading in metal commodity is challenging, trading gold could be profitable but need higher balance.
You can adopt some tactics to higher your profit ratio. Except for so, there is nothing you can do for certain to reduce the loss ratio. You can trade any pair with FXOpulence broker because they charge narrow trading spread to traders.