What you need
Enchanting 400 (judging by the difficulty some people are having with this drop, which is very unusual because it takes me a few pulls, I am confirming you probably do need at least 400 enchanting which is the recipe minimum.)
Character high enough to kill the Skeletal Runesmiths from this infamous spot http://http://thottbot.com/c30921
The item you are going to farm
Formula: Enchant Cloak - Superior Fire Resistance
This sells for 200 on my low pop server.
Always post below the tenth spot though so 199g, usually takes at most 48 hours for one to sell.
The Trick
The drop rate on this item says 1.8% which is far to low.. it's actually around 95% IF YOU DO NOT HAVE THE SPELL LEARNED ALREADY OR ON YOU. Most people who are enchanters get the spell and learn it, this will ruin this guide/exploit because it will not drop again.. what I do is farm the item in 20 seconds because it takes me 1-3 kills, mail to an alt by either putting down a portable mail box or flying back to Dalaran, and then I start to farm for it again. It will not drop again with one in your bags or if you put it on the auction house with the character you are farming with, hence the alt. I can get as many of these as I want and they always sell for 200g making me a wealthy gamer. Only put one up at a time, do not flood the market.
The same tactics can be used on the other enchant drops and i would imagine other profession pattern drops.
-Justink15