Time to level up alts!
Into Tanaan Jungle
Felblight can only be obtained while in Tanaan Jungle, and you can get it by killing bosses, rares, regular mobs or by using gathering professions.
Supreme Lord Kazzak
This is my favourite, without a doubt. Simply look for a group for the new world boss, Kazzak and participate in the kill. He's very easy and fast, and drops up to 15 x Felblight. Currently it sells for 300-600 on most realms and sells almost instantly, so if we assume you get 15 and they sell for 400 gold, that's an easy 6000 wow gold.
What makes this even better is that you can do this on all your level 100 toons and every week when the loot lockout resets. 6000 x 10? Oh yeah! Not a long time ago you could have done this with even lower level characters, but it was nerfed.
This is not a very effective way of of farming Felblights, as you could end up killing a thousand and get only one. Rare mobs do have a higher chance to drop them, but it's still extremely low. Rares are abundant and drop other cool stuff too, though.
Fishing is a good way for some people to get Felblight, provided you find lots of Fish Schools and get lucky, as the drop rate is only about 3-6%, like with all gathering professions. You also get a boatload of fish that you can sell. Fish from these schools usually sell for only one gold, though.
There are a lot of places where you can fish, but personally I often like to seclude myself in a "hidden" cave that I've never seen any other player in, yet it contains a few Felmouth Frenzy Schools, hidden treasures and a rare mob. The cave is not abandoned though, and even the fish will aggro you! So have a weapon at the ready. A good idea is to dive into the water and AOE the fishies, and then proceed fishing...
So if you're on a PVP realm and prefer to half afk, and don't want to worry about being stabbed in the back while you're wielding a fishing pole, this is one of those places.
A very secluded cave, filled with monsters and fish!
|Ruins of Kra'nak|
A smooth fishing route with lots of Felmouth Schools!
All nodes in the jungle has a chance of giving a Felblight when mined. I have had a very long pause from wow, so majority of my toons aren't level 100 yet, including my Miner, so I haven't yet researched the best farming route. But will update this post if I can be arsed to level my miner up. Unlikely, though!
All flowers also will have a chance of dropping a Felblight when harvested. My herbalist is also not level 100 yet, so I haven't tried how effective herbalism will be, or what the best route is.
The drop rate for Felblight from skinning was nerfed significantly, but you can still usually get one Felblight every 10-20 skinnings.
Here's the top 5 mobs to farm for Felblight as a Skinner and where to find them, in no particular order: