Best way to earn gold with Mining and Jewelcrafting?

I was wondering what the best way to earn gold would be for my main. I have Mining and Jewelcrafting as my main professions, and although I have profession toons, I'd like to try making enough gold with just my main. Is there a specific ore I should farm (and should I smelt it), for example? I don't know much about how to farm gold in WoW, being a somewhat casual player. I know there are tons of other ways, but I just wanna know about what I can do with a single toon with Mining and Jewelcrafting.