2-3K Gold in Pet Value In 2-3 Minutes each day (Patreon)

(Warning: contains pet battle content, though you need to know nothing about pet battles to make money from this exploit).

The "Pet Battle Event" has just started. This awards triple pet xp when levelling pets during the holiday. 

Despite the stigma around pet battles they are one of if not the most profitable thing to do in warcraft, and the system can be gamed quite easily by exploiters.

The following strategy is a very simple one designed for players who know almost nothing about pet battles.

Acquire 2 level 25 pets  off the ah and a third level 1 pet that can be "caged" (you probably have some in your inventory already). Port to your garrison, picking up the quest "Battle Pet Tamers: Warlords" and go to "Ashlei" , a Draenei infant, outside Embaari village in Shadowmoon Valley, Draenor, and click on the blue exclamation mark over her indicating her daily quest.

Ashlei can be beaten relatively easily using basic damage attacks by any two random level pets. Only two of her pets actually attack - the third "Doodle" simply stands there while your pets attack. Kill Ashiel's other two pets with your level 25 pets and then switch to your level 1 pet when Doodle appears-after one round switch back to your 25's. 

Ashlei offers very high levels of experience - your level 1 pet should attain 18 levels. You will also receive two pet charms. 

The point of this strategy is to raise the value of your level 1 pet and then sell it. A pet with a higher level is worth more on the auction house.  I have found the "spread" between a level 1 pet and the same pet at level 25  to be an average of 3000 gold (though it may be more or less depending on the pet). 

I would use a different level 1 pet each day. The xp needed to advance a level gets higher so you don't want to try to level a pet from 18 -25. Instead use your pet charms when you have enough to buy "flawless battle stones" which cost 3 pet charms and raise your chosen pet level by one. You will also receive 10 flawless battle stones for beating Ashlei 5 times from the "Battle Pet Tamers: Warlords" quest. 

The exploit with this strategy is to park a class trial character next to Ashlei and use that character exclusively for pet battling this npc. That way the whole process takes only a few minutes at most with practice.  The lack of downtime makes the process much more efficient.

An alternate strategy if you have a 90-100 character is to use this method to level your pets and your character (pet battles award player experience as well as to the pets).

For players interested in making very large amounts of gold from pet battles I would look at Xu-Fu's online guides and, particulary at looking to level pets during pet battle weekend vs "Squirt" in the garrison menagerie. This post may be of interest to very advanced exploiters:  http://www.ownedcore.com/forums/world-of-warcraft/world-of-warcraft-guides/556081-auto-level-pets-when-youre-afk.html