World Events of WoW are (almost always) a good opportunity to earn gold. Noble Garden is no exception. The good part of World Events Gold Making is that these tricks keep on working year after year.
As you might know, you have to put “rabbit ears” on female of different races, Alliance and Horde.
Under Burning Crusade, where we had Shattrath and under Wrath of the Lich King, where we had Dalaran, it was a pretty easy quest since Horde and Alliance were in the same city. You just had to run around and put ears on the races you needed to.
Nowadays, it is more complicated. You have to come in contact with the other faction and on PvP realms, it can be a bit slightly difficult thing to do.
Besides, there are races where it is very hard to find a female. That goes on Alliance side for the Dwarves and for the Horde, it is the Tauren. There are very few female characters of those two classes.
Once upon a time, when I started in WoW, you could not have characters from both factions on a PvP (or RP PvP) realm. That meant that if you made an Alliance character, you could not make a Horde and vice-versa. This restriction has been lifted long time ago so you can currently have Alliance and Horde characters on the same realm, even though it is a PvP realm.
Now, let’s say your mains are Horde.
Make a female Dwarf. Level her to 18 which is the minimum level needed to get ears on. You can send her heirlooms to speed up leveling. Heirlooms can be sent back and forth between your characters cross faction, but for the time being, you can’t send other things than Bound on Account things (no gold, no bags, no “regular” gear).
When it is done, the best thing is to try to get somewhere where you can be easily found for both factions. This year, I placed myself in the Darkmoon Faire, somewhere in the zoo. But you can place yourself anywhere else, easy to access: Dalaran or Shattrath for example.
Then you have to wait. Wait for the last day (or the evening before the last day) of Noble Garden. It will be the time where some will be desperate enough to pay.
Access your faction’s trade channel (or the opposite faction if you want to) and make an announcement: Anyone needs to put ears on a female Dwarf (or Tauren) ? I have one at your disposal for 50 gold.
You take payment from the character who announced, and you can either give the coordinates, or have another character around who can group so your client knows where to find you.
Believe me, people are ready to pay loads of gold to be able to get this achievement (which give a title and is part of the achievements needed to get a mount later).