Latest patches changed the loot a bit.
for Alliance the best and fastest way to do it:

• Start at Teldrassil or Azuremyst Isle.
  From Azuremyst you can leave at skill 110ish, from Teldrassil it's about 100.
  
  
• Grind in Darkshore and Nort-Western Ashenvale till you reach skill 125 (Kingsblood-capability)
  
  
• Next stop is Menethil Harbor and Wetlands. Grind untill you can collect Liferoot, meaning you have reached skill lvl 150.
  
  
• Move to Arathi, start grinding at the North-Western corner and in the middle area, then move to the cliffs for Khagar's Whisker. This means that you have reached skill lvl 185. You will find many whiskers by the cliffs all around Arathi, easy to get to 210.
  
  
• Move to Stranglethorn Vale
  
  
• from this point, it's pretty much the same as mentioned before (I'll test Tanaris), will edit this post if patches would change the situation.
  
  Good luck, guys, have fun!