Originally Posted by 
Niwashi
				
			 
			If you don't like over-leveling content, you can pick up a second class and alternate quests between two of them to spread out the XP enough to stay on track with the main scenario levels.  Or you can just wait it out, because later in the game, as it takes more and more XP to gain successive levels, your quest levels will tend to catch up with you.  Plus, in the meantime, instanced dungeons are level-synced anyway, so being over-leveled is really only an issue for the open world portion of the content.
Oh, if you're the type who likes to keep re-running dungeons until you get all their good loot, that pattern can definitely make you out-level your quests quickly, even in the later portions of the game where leveling takes longer.  So I'd definitely recommend this sort of loot farming be done on alternate classes.