Since I haven't figured out what I wanna play, I just level all classes on each of my 5 accounts to level 80 with RAF. Figured I'd do that first and then mix and match them into groups to level 80-85.
With RAF xp bonus + 4 heirlooms (=35% bonus) and using a booster, I can go 1-80 in 3 days (RL, not played).
I highly recommend you just level stuff until you wanna poke your eyes out, and then level another team