This is how I decide my commendations:

1. Have I popped my challenge? If yes, go to 5. If no, go to 2.
2. Will this pop my challenge? If yes, go to 3. If no, go to 5.
3. Am I a class that will benefit from the bonus? If yes, go to 4. If no, stop.
4. Is there another class that I would rather get the bonus? If yes, stop. If no go to 5.
5. Is anyone still in the dungeon? If yes, go to 6. If no, stop.
6. Did anyone positively stand out in a social manner? If yes, commend. If no, go to 7.
7. Did anyone positively stand out in a gameplay manner? If yes, commend. If no, go to 8.
8. Was anyone new? If yes, commend. If no, go to 9.
9. Did anyone have an amusing/interesting name or glamour? If yes, commend. If no, stop.

While I wish there was a system that allowed us to give a more in depth review on a person's performance by role or job, I know it'd never happen due to ease of abuse and general apathy.