If you are looking for the best way to make gold in WoW you have come to the right place. There are plenty of things you can farm, and things you can kill for some amazing loot, but you need to prepare a few things before you set off to make your thousands.
The most important place to start is with your backpacks. It is important to maximize your inventory so you can carry more items per trip. If you are out to make as much gold per hour as physically possible, it is important to waste as little time as possible transferring or selling your items. I would advise that you get no less than 18 slot bags, and if you can afford them buy some 20 slot bags before you set out to make your thousands.
The next place you need to start is with a bank alt. This is a character that you will make for the sole purpose of selling your items. Any items that you do not sell directly to a vendor you will send here. It will greatly help if this character is higher level and can disenchant your BoE greens as well, although many players will not like the idea of leveling a character to be a bank alt who can disenchant. If you do this one step you will save a ton of time and energy down the road.
It is important to maximize your inventory space here as well, but nowhere near as much as it is for your main character. Once you can afford to up your bag space on this alt you need to do so.