Multi-questing. No, I'm not talking about doing multiple quests at the same time, I'm talking about daily quests you can do as a group and get credit for everyone in your group with.

So (mostly) off the top of my head, here goes:

In Shatt:
The goggles quest in Nagrand, everyone gets credit for each fire you sample.

The get the missive note from the sunhawks, it drops for everyone in the party.

On Isle of QD:
Arm the wards...