I've done this on both a hunter and blood death knight.
https://i.imgur.com/zfqv6.jpg
You'll want to go to this area, I was able to grind out a level in about 80 mins up to 87.
The mobs drop a lot of greens, motes and cloth. I was getting 20+ stacks an hour.
the mob you'll be wanting to kill is an instant respawn named the Outcast Sprite.
Outcast Sprite - NPC - World of Warcraft.
Chain pull them, and aoe down. they respawn fast.
Enjoy.