I really like these two posts over at The Chaotic GM:
Thief Buffs for Dungeon Fantasy
Martial Artist Buffs for Dungeon Fantasy
The thief ones I can get behind very strongly. The martial artist ones, less so, but only because I have my own, different approach. One I'd like to see in print when I have the time to write it. But I endorse both of these as good reads and potential sources of ideas if you're unsatisfied with how the thief and martial artist templates turn out in your own DF games.