#1 Best place to farm Embersilk Cloth:
1). Get a tailor. Level it if you must.
2). Go to Tol Barad (requires Level 85).
3). Go to the Area where you are supposed to kill the ghosts of Horde and Alliance that are fighting each other (in the Southern Portion of the Non-PvP zone, with the siege engine wreckage, near the graveyard hill). Be careful of Hellscream's Watch (the Horde Base) if you're Alliance, those guards are wickedly powerful.
4). Kill lots of *bleeep*.
When you attack a pair of ghosts fighting each other, make sure you hit BOTH the Dwarf and the Orc ghosts before killing one or the other, if you only hit one and kill it, the other will heal back up to full.
The mobs here are much weaker and easier to kill than any normal Level 85 mob, but yet seemingly drops the same amount of Embersilk Cloth as any other Lv85 does. The mobs only have 70k health IIRC, but are usually half-dead from fighting each other.
The scavenger orcs walking around have 56k IIRC and are wimps, and are non-aggressive.
Barring unlucky aggro (a dwarf or orc popping by itself), there is almost zero danger and the mobs respawn very fast. As a bonus, there's only 1 quest that wants these mobs, and few people even do Tol Barad dailies anymore.
If too many peeps do this too much, I can't guarantee it won't be patched. But surely, this late in the expansion, Blizz had to have known this exists. I've done this as recently as Patch 4.2.2; I don't know if it has been changed in Patch 4.3, but I don't recall anything being posted about it.
Edited, Jan 4th 2012 10:23pm by Lyrailis