I found this the other day at one of Sister Spitfire's blogs, courtesy of A Catholic Mom in Hawaii.
Mother Teresa gave these rules to her Sisters to help them develop the virtue of humility:
1. Speak as little as possible about yourself.
2. Keep busy with your own affairs and not those of others.
3. Avoid curiosity.
4. Do not interfere in the affairs of others.
5. Accept small irritations with good humor.
6. Do not dwell on the faults of others.
7. Accept censures even if unmerited.
8. Give in to the will of others.
9. Accept insults and injuries.
10. Accept contempt, being forgotten and disregarded.
11. Accept injuries and insults.
12. Be courteous and delicate even when provoked by someone.
13. Do not seek to be admired and loved.
14. Do not protect yourself behind your own dignity.
15. Give in, in discussions, even when you are right.
16. Always choose the more difficult task.