A new quest will pop up once your first pet reaches level 3. It will send you to either Audrey Burnhep in Stormwind or Varzok in Orgrimmar. These trainers will offer a quest chain to battle specific Pet Tamer NPCs on each continent. Defeating each of these NPCs will reward a nice chunk of experience for your pets, as well a Sack of Pet Supplies (which has the chance to drop the Porcupette companion, among the always-useful pet bandages).
Most classes in World of Warcraft start at first level, but Death Knights and Demon Hunters are exceptions. They start at level 55 and 98, respectively. This alone can shave a huge chunk of time from your leveling experience. Of course, it only works if you want to play a Death Knight or Demon Hunter, but they’re both solid classics that can dish out damage or tank in a group.
Always updated: Zygor‘s is completely updated for the 5.4.2 patch and will be for all subsequent patches and expansion, including Warlords of Draenor. You’ll be able to do the blast to level 90 (and later, 100) in very good time and get into all that good end game stuff. It does this with an easy to use updating widget so you will always be up to date.
Finding the best route for you can be a bit tricky because of the size of the dungeon. I will usually only do about half the dungeon, killing as many mobs as I can in 6 minutes. After 5 minutes, make a group in the group finder and leave it. That will leave you a minute to complete your 6 minutes and you will be ported out on the 6 minute mark, ready to reset and port right back in.
Level 65 unlocks Greater Invisibility. This can be used to instantly escape combat with any enemy, or reduce the damage of big hits by 90%. Keep in mind, when using Greater Invisibility, you will drop combat, and lots of enemies will start evading and healing back to full Health, so do not use this on low Health enemies if you would survive the hit.
This farm almost did not make this list. Even though I have had only a little luck with it, it seems to be gathering some popularity in the gold farming community. Although I feel with the recent changes in 7.3, this farm is very close to dying out. Generally what you want to to do is pull every mob you can as you venture to the last boss in the instance. The only saving grace of this farm (if you can call it that) is that some mobs are GUARANTEED to drop greens. Guaranteed. Whether or not they drop profitable greens is a different question, however it's a must-mention quirk you get from running this instance. It also allows you to get your hands on some rare low level blues.