How to Level Up to Three Times Faster in World of Warcraft

Firstly, I would like to let you know that this guide is no lie, and doesn't even depend on the player. Anyone can actually get triple experience through my methods.

Refer a Friend
The new refer a friend system that Blizzard has launched is an excellent opportunity for you to take advantage of whether or not you want to actually recruit a friend.
How it works: Through this system, you send a friend a trial cd key, you can even send this to yourself. You then install that product, and then simply upgrade the account to at least the basic retail version of World of Warcraft.

Benefits: You will receive endless benefits from doing this for a friend. Firstly, while grouped with the friend who you recruited to World of Warcraft, you will get 3x experience for anything that's not gray to either player (not worth any experience). The recruiter (veteran account) will also have access to a free month of WoW service after the recruit pays for their first full month of WoW or sets up a subscription. Also, after the recruit pays for the second month the veteran account receives a free epic mount, the Zhevra, saving the player hundreds of valuable gold.

Addons
If you can't afford to do this or can't find any friends to do this, there are many other ways to get experience through the honest way (without hacking, cheating). Addons are one of these. Try getting leveling guides combined with quest helpers. I do NOT recommend the "Quest Helper" addon for anyone interested in efficient questing. Download carbonite from curse.com. Also, get the WoWBros leveling guide from curse.com as well, this will tell you where you should be questing at each level, as well as which quests to do in each area.

Class
I would say that there are definitely some classes that have a major PvE (player versus environment) advantage over other classes. I would have to say that hunters are the fastest leveling class because they can take down targets quickly and efficiently, and can even handle mobs when their pet is correctly used. Warlocks are also excellent for this. I would say classes like rogue and warrior are much more difficult to level with.

Instance Runs
You'd be surprised how many high level players would be more than happy to give you a run through an instance for an achievement. Runs through instances, if done properly and at the correct level, can gain you tons of levels when done quickly, as well as get you good equipment to level faster while on your on.

Most of all, I would say the best way to gain levels quickly is to simply love your character and class. Do what you like, and the levels will come easily. Don't do something just because it levels fast, you're going to end up wishing you had done something differently. Have fun!