In Tanaris you can hunt Ogres in the south-western part of the zone. They hit quite hard, but like all Ogres they do not run Eve isk and have humanoid drops.
There are two chests in the area which are another source for good equipment.
Low-50s: In Western Plague lands, the first farm known as Felstone Field has very reliable monsters that always spawn in the same area. In time, this area can be an excellent place to farm experience and money.
There is a chain of quests that can be accomplished while you hunt that start at the Bulwark at the border of Tirisfal Glades and the Eastern Plague lands.
Upper-50s: In Winter spring there is a frozen lake where there are a number of monsters that are spaced far apart that can be defeated while going in a circle around the lake. At an even pace you will never run out of monsters to fight in this way.
Also in the Badlands are the Ogres which are like every other ogre everywhere. The only easy humanoids to grind in the Badlands however and they aren’t a terrible choice for their humanoid drops. They also don’t flee when they near low health which is a plus.