Discovered a nice source of Experience points. I think everybody probably knows already that you often gain Experience for looking at various things. Found in addition that if you 'list' the items for sale in the shops, you gain Experience as well. This can be a nice little plumb: there are quite a lot of shops in the Black Plaza Mall, for instance.
Seems to be the case that this Experience is awarded only once. That is, if you return to the same shop and 'list' again, you're not awarded more Experience. Maybe one of the high-level immortals could confirm?
I'm currently at Level 4, and have found so far that it's not too hard to gain those early levels.