Embersilk Cloth Farming in Twilight Highlands (Nagas)
Another good place that I found to farm Embersilk Cloth is from the nagas in Twilight Highlands. The nagas are on the eastern part of the zone, just north of Dragonmaw Port. Only the Horde have a quest for the nagas and the nagas run up the shore to battle the Horde NPCs... For this reason I actually only recommend this location to Horde, at least if you're on a PvP server. As Alliance the chance of you getting ganked on a PvP server is just too high. However, on a PvE server you will have nothing to worry about of course!
The nagas have a pretty good drop rate for Embersilk Cloth, probably roughly around 40%. There are two things that I really like about this location. One is that the nagas will constantly come running out of the ocean and onto the shore and the second is how easy the casters are to kill. Two types of nagas comes out of the ocean, warriors and mages. The warriors aren't nearly as squishy as the mages but they will go down pretty quick regardless. There are two added bonus' of this location, first is if you're a Shaman, you will get a nice stock of Shiny Fish Scales and Fish Oil for your spells. The second is the nagas drop clams which contain Blood Shrimp which you may be able to sell on the Auction House depending on how many people on your server are leveling Cooking.
Ruined Embersilk Cloth
Shiny Fish Scales
Embersilk Cloth Farming Video: