I have been leveling my Dragoon through the story, but also other than the first weekend of early access, have been doing the high and low level roulettes on my White Mage. Guildhest roulettes too. As a result my Dragoon is now lv57, but White Mage is also halfway to 54. It seems like Dungeon Grinding even once roulette bonuses are done will be the best way to level. Although doing so on a DPS probably will be a little more annoying with the queue times.

Also I have a feeling that FATEs might pick up once more and more people unlock flying in every zone and start working on second jobs. Boosting the FATE exp a little would be nice too. FATEs giving 20k exp when you need 3 million to level makes them not worth the effort right now.