My apologies on two counts. First, for reviving a four-month-old topic (I'm not sure the feelings on that around here). Second, for offering suggestions when I'm new and haven't proven I'll stick around. I was curious about titles, however, and came across this thread. Since the question still appears to be open-ended, I'll offer my two cents, for better or worse.
0 - Novice
10 - Apprentice
25 - Skillful Tyro
50 - Mage
100 - Adept Sorcerer
200 - Shade Spellcaster
400 - Wizened Sage
500 - Choose your own title
My reasoning: 'Tyro' still has beginner connotations, while mage doesn't, so it made sense to me for them to be switched. While I don't pretend to know anything at all about the occult, 'Occult arts practitioner' seems a little general, 'adept sorcerer' is probably no better, but it's what I could think of off the top of my head. 'Wizened sage' just sounds good to me. I offer these opinions humbly, and, again, mean no harm in digging up old questions.