This trick requires that your character has a major skill of Sneak and 
either Destruction or Alteration. If
your skills are Sneak and Destruction, gain access to Arcane University. Go 
to the area to make spells.
Make a Drain Health spell that is set to "Self" and only uses 1 Magicka. 
Then, go upstairs. Go into Sneak
mode and just run into the wall without stopping. Activate the magic spell 
repeatedly to gain levels quickly.
Note: When you activate the magic spell it will seem as if it is hurting 
you, but it is not. If your skills are
Sneak and Alteration, go into a room with a container (for example, 
cupboard, drawers, etc.). Run into
the container in Sneak mode and use a "open very easy lock" repeatedly on 
the container.