Gold for riding training. Travel time is a SIGNIFICANT time sink while using quests to level. You don't want to wait to get it. In fact, while questing, the second you ding 40/60/70/80 you'll want to hearth and train it IMMEDIATELY! 10304 gold is the base cost, which will be modified by reputation. Also, make sure you're in a guild with the 10% riding speed bonus unless you're a class that already gets a mount-speed buff.
Making gold is all about finding the balance that works best on your server between all the above methods. When you find that balance, repeat, repeat, repeat, until you get the results you want. Never make any rash decisions without first consulting the economy. If you do not think you can make a for sure profit, then do not do it! Change only when necessary, because your clients become accustomed to certain practices that keep them buying from you even if under cutters offer a slightly lower price. If the customer is always right, then show that to them and you will be much more profitable!
I highly recommend actually staying in the 20-60 range zones until you ding 62. The reason for this is that despite getting a slight penalty in experience for being over-level, the advantage of having flight will more than offset this. That, and WOTLK and TBC zones are the slowest part of the leveling process. Minimizing your time there as much as possible is worthwhile.
Christmas is here and the Winter Veil Presents can now be opened in US and EU regions! Whether you've been naughty or nice, Greatfather Winter has a nice surprise waiting for you to collect in Orgrimmar or Ironforge. The Winter Veil presents will be available until January 2, and opening one will also reward you with the He Knows If You've Been Naughty achievement.
Some people have made arguments that quest blues can sometimes be more powerful than heirlooms, especially with sockets. I'm not convinced. The simple fact that you never have to even look at quest rewards will save a non-insignificant amount of time over the course of leveling. Also of consideration is the value of enchanted gear never having to be re-enchanted.
The last farm on this list, actually I was surprised this farm eluded me for so long. Generally speaking gnomergan is a huge confusing instance that takes some getting used to but if your a high value transmog farmer this does not scare you. You can pull the entire instance and get access to a plethora of high value loot such a recipes, world drops, greens and even engineer supplies. Overall this farm is shadowed by the Diremaul farm and Zulfarrak farm, but is an equal change of scenery with a wild card if you get the hot shot pilots gloves OR the mechbuilders overalls worth 400,000g and 60,000g respectively. A pretty cool neat farm that noone really mentioned until now.
Now that we have a lot to post we reached a point where we have to plan what items we post on an 12-24-48 hour cycle. The auction house fees for Warlords of Draenor items are extremely high. And the values of the items are really screwed up. A lot of the weapons or armor has an item value of 5-10.000 Gold. But they look plain bad and the chances of selling them is pretty low.