Lately I've been toying with the idea in my head of removing combat feats and instead making them 'combat techniques'. This idea is to make them similar in mechanics to how a prepared caster can learn spells, martial characters can learn techniques. This is to bring a level of realism to the table as fighters can learn techniques from different sources such as a master or a scroll that describes an ancient technique thus picking up different styles. There might be a limit to how many techniques a character can learn that raises by level. Their BAB would be the limit to how advanced their techniques are. Instead of Fighters getting combat feats, they develop martial techniques as they level up (similar to how wizards get spells).