Just my two copper featured this spot to farm eternal fires in storm peaks. Its in the little cave in the north east end of the map. You see 2 caves. One has eternal air and the other eternal fire. That is the best place in the game to farm eternal fire.
If you take the right class its almost insane. As a ret pally you can mow them down non stop. even pulling 2-3 at a time. The do a little stun but your probably waiting for a cooldown anyway. You can kill them almost at a fast pace as you race up and down that cave. The faster you can kill them, the faster they spawn. My record farming session got me an eternal every 4 minutes.
There is a camp close by so you can go vendor,repair, send mail and get back to it. Even when when you have to share the cave, the rate you get eternals is very fast. If you can do a zone coverage, you will both make out better then racing from mob to mob.
I used to make this my afk spot. After raids or while waiting on groups to get started, I would just work that cave. The greys alone turn a good deal of gold.
I tried that same thing on my priest because I was in the area and needed 2 eternals. It turned out to be very frustrating. The stuns and constant adds were just to annoying. So if you struggle there, try an alt instead. The drop rate is still good, just have to be killing them fast.