In Game Feats
Characters can choose a feat to be studying. They can learn it using a teacher, divine intervetion, trial and error, practice, whatever seems reasonable. You can attempt to activate the feat on a roll of 15 or better. Once activated you can use the feat for that round.
Once you have succeeded at using a feat at least five times over at least three adventures, you can gain the feat permanently. A character may only study one feat at a time.
In Game Skills
You can learn a new skill in a similar manner. If you find a teacher and spend time practicing, you can gain 1 rank in the skill. You can only do this once per adventure.