I think the best way to earn gold is dedicate the first few weeks+ in the next expansion to doing nothing but herbing and mining. I did a little of that in previous expansions but get in a hurry to level up. I regret it every time. Im willing to guess that if you focus on farming gold now.. all the gold you could earn now wont equal what you will earn in the first weeks of shadowlands. Now that is not to say that you cant make a ton of gold now,,but i dont think you need to focus on it. Right now if you have any teams ( even one ) that is exalted with all the emissaries, just doing WQs nets thousands of gold Via the supply crates ( 4k+ each time )..also disenchanting items you get as rewards, there are a few that reward gold as well..Random emissary 2000g reward ( thats 10k a team ). Also.. just playing the game as a boxed team nets a lot of gold for assaults and such. Of course.. the more teams at 120 you have the better for WQs. And the more of them that are exalted even better.