Quickest way to level

[Psotnik]

Challenge Log (resets every week so always has extra exp) and Duty Roulette Low Level (random dungeon, resets everyday, huge Exp bonus).

You can also farm FATEs or Leves just like the "old" days.

Hunting logs, crafting logs all depending on what you're doing but i agree leves are the best way to go. I have seen where its said Miqo'te leve cards are said to give the most overall with bonuses and such also heres a link that might help you as well to decide http://www.usgamer.net/articles/fina...ys-to-level-up