If you ever run low level instances looking for a rare boe item with a low level buddy in Azeroth instances, here's a helpful hint that lets YOU (the high level) avoid having to loot all of the trash that drops in there, and lets him get everything but what you want:
Change the looting in the group to Loot Master
There's a (new?) setting -> Pass All Loot
For Loot Master, change the limit to Rare
With these settings, you (the high level) will only see loot sparkles on mobs that have a rare (blue) item or better, and saves you having to check each and every body. It saved me a ton of hassle farming low level zones for boe rares. If you're power leveling enchanting, you can set the loot limit to Uncommon, and loot only greens (also very helpful).
TLDR version:
1. Group with someone in a low level instance
2. Set Master Looting, limit on Rare, with "Pass All Loot" enabled
3. Never loot anything without rares again
I have two accounts, so I usually invite a random alt from a second window and minimize it while I go in solo with my 70.