So, how about a system where, for each advanceable attribute/skill/ability/whatever, there’s an in-game goal that needs to be reached in order to get it? Frex, to get the first rank of “Archery,” you need to convince someone to teach you. To get the second rank, you need to have a successful hunt. And so forth. If the situations were laid out by the game, I think they’d have a strong potential of just “missing” some characters. So perhaps the players/GM could make them up as they go. The advantage I see to this is that what is being rewarded matches well with how it is being rewarded. Also, it includes learning in the story in a significant way.
An Idea on Character Advancement