Making World of Warcraft gold from questing is a great and fun way. You can get lots of WOW gold and the bonus gold based off the amount of experience you would have earned for doing the quest. If you refrain from spending gold on your way to do World of Warcraft power leveling, you'll notice a substantial gain from questing and from either vendoring or disenchanting your quest rewards. There are two ways to make WOW money by doing questing.
The first efficient way is to complete regular quests you didn't do prior to turning level 70. If you do all of the quests in Netherstorm after hitting level 70, you can get as much as 2000 WOW gold. For me, I like to save Blade's Edge Mountains, Shadowmoon Valley, and Netherstorm. Usually I don't do all of the quests one after another, but when I am bored with other WOW gold making activities I go back to the zones and knock a few quests out from one of the quest hubs.
The second way is to do the daily quests. These involve everything from Cooking and Fishing dailies, to Dungeon and Heroic Dungeon dailies, to PVP and faction specific dailies. Basically, these are quests you can do over again once per day each, up to 25 total as of patch 2.4. Besides World of Warcraft gold you can also gain faction with certain groups, which provide rewards including unique mounts and useful items.