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.
The entire Jade Forst is our farming spot for this one.  Literally, the entire Jade Forest.  The Jade Forest is crawling with porqupines and if you have a mage character, each one of them has chance to drop the polymorph porqupine tome.  Which is excellent, because these tomes have a selling point of 13,000g across the board. They are really easy to get, and noone really pays attention to these spots.  Try it if you like, I was able to get 2 on video, and have already sold one of them.  
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.

Step-by-step class guides are on the way!  The 1-12 Mulgore Guide is the first guide to get all the individual class steps.  At the top of the guide, simply select which class you are playing and the page will dynamically update all the steps in the guide for that class (both text and images).  The rest of the guides will be slowly updated overtime to include all the class steps, but you can see how it's going to work with the 1-12 Mulgore.  I want to thank crazyK and his Placeholderguild for helping me out with the individual class content.  They are allowing me to get the 1-60 Alliance guide done while also getting all the class steps done at the same time, so everything can be ready for Classic launch (hopefully).
This was a farming spot that I made vastly popular on YouTube sometime last year.  It is my FAVORITE farming spot of that era, simply becuase it was an old world farming spot that allowed you to hit almost 3 different markets.  With this spot you can get cloths:  Felcloth, runecloth, and mageweave. Herbs:  Goldthorn, ghost mushroom, goldclover, and fadeleaf.  World drops: rich purple shirt.  AND a plethora of transmog from a single run.  I literally had some pulls where I came out with 17,000g in item value for 10 minutes of farming.  It was insane – actually it still is.  Anyway If you have a druid or monk, then this is an awesome farm to hit ESPECIALLY if you are on a high populated server.  Generally just pull the entire instance, and circle it back around the front.  Mega gold to be made here.
Another potion of treasure finding farm that was made extremely popular by the YouTuber Oldbess.  In this spot, you are simply to patrol the entire southen river basin in Twilight Highlands, just around the Verrall Delta area.  The goal of this farm is to kill water elementals for their volatile water, which trends around 50g per drop.  Combine this with the cloth and the treasure chests, and you have a cool  nifty farming spot – thats rarely populated these days.
The most rare and expensive poly morph tome drop and for a reason.  The bears that drop it are VASTLY spread out across the zone and getting one can mean hard farminh for a while.  They also take a while to respawn so watch out.  Getting one to drop can mean a staggering 48,000g, and on top of that compared to other pet farms and such, they have a much higher drop chance.  Simply head over to dragonbligh ona mage character (class trial is perfect) and start the killing.  Cross you fingers as there is an 0.4% chance to get one on each kill.  Thats actually pretty high considering..
When you enter the world, you will find other characters nearby with a yellow "!" above their heads. Whenever you see a character like that, it means that this character has something he needs your help with—a quest! Talk to them by right-clicking their character. They will offer you one or more quests via the quest dialog; clicking Accept adds the quest to your character’s Quest Log.
This spot actually kicks BOOTAY.  And I only say that because it's so hidden, unique and quirky that I had to add it to this list, despite it being a method rather than a farm.  Generally what you want to do is some sneaky arbitrage.  We'll be buying the items Royal olive, Dalapeno Pepper, River onion, and Muskenbutter from the vendor for 2g – and reselling them to the AH for 4g+. This is an awesome way to take advantage of players laziness and the demanding reagent requirements for some of the higher end recipes.  By selling from the vendor to AH, you can make easy gold – in fact I suspect most cooks do not know these reagents can be purchased from NPC's.