Outlands, for me was non collection quests in Hellfire, Zangramarsh, Terrorkarr Forest, Nagrand, and if I wasnt 70 by the end of Nagrand, then i hopped over to Shadomoon Valley. It was hit and miss if I need to go to that last zone or not. You wont have to if you migrate to lich king at 68. I also do all the ramparts quest and blood furnace as well as a couple in Underbog. Theres a few collection quests in Zangramarsh that I do because you can trade the quest items like unidentified plants and glowing spoors and sanguine hibiscus's.

Anytime I had extra rested xp to burn off, I would just run Underbog to the first boss. Everything in there is easy sauce standard tank and spank.

The Goblin zeplin crash site in Hellfire is full of fail quests for multiboxers.