My first toon leveled up mostly through questing, but that was long ago, before One Tamriel, when the grind for veteran levels took forever. As for my second, well, my method of choice was violence, lots and lots of violence. The poor *** practically lived at the Rimmen Necropolis until he reached level 50. I waited for double XP events to log on that character and spend a few hours ruining some skellies' and daedra's day.