Level in Wrath, a little at a time.
Not really sure why, but have liked Wrath leveling least of all.
Granted classic wow leveling for boxing was via RAF.

Still, a little here, and a little there.
Always with rested.

Sometimes, watching a movie or dvd series on TV.
And have the leader toon tab and nuke, tab and nuke.
That's pretty painless leveling, considering you aren't even looking at the monitor.

Every now and then, you get a new toy, Lava Burst for example.
For a while, its exciting to blow everything up.
That definitely helps the leveling pace.

Quests or instances are the only good options, if you're paying attention to the game.
It comes gradually, don't let the game burn you out.