Well-known World of Warcraft gold farming game guides stresses that one of the best ways to get tons of WoW gold is to become a businessman. Think of yourself as a merchant - selling items that you find during quests or buying sellable items for cheap and selling it out at a higher price.
Though it's true that bashing monsters is quite fun and going on a quest with your buddies takes up all your time in the virtual world; but keep in mind that there is always a possibility of earning gold with every item you pick up. In most cases, hoarding might eventually become your first stepping stone in becoming a millionaire in WoW.
Some gold farming guides focus on items called cloths. There are two of them that you need to watch out for - the wool cloth and mageweave cloth. These two necessities are dropped by monsters. Shadowfang Keep is a well-known area in WoW that drops wool cloth and mageweave is an item you can quest in Zul'Farrack. If you got a lot of them then you're rich - wool cloth sells for 10 while mageweave go for 12.
If you're an Auction House regular in the game then you might want to get your hands on some infinite dusts. These are high-demand quest items that can be only found in auction. Try to look for one that is for sale at a cheaper price. Hoard as many as you can and sell it off at a higher price - after all; they need it so they will pay any sum just to get it.
Becoming a businessman in WoW is just one way to get a lot of WoW gold into your pocket. Some go for quests to find rare loots and sell it off for a bigger price. As mentioned above, many go cloth hunting in hopes to get a lot of them and opening up shop for both fun and profit.