Couple of things to add there.

Grab leves for the zone you will be questing, as its extra quests in the zone. If, on your way to a quest and pass a FATE in progress, jump in or just do enough to earn gold and move on if no one there. It's still XP and both add up. I got to 60 on MNK and still had some 56 quests, majority of 57 quests and all of 58-59 quests left for levelling PLD.