These are the fancy occasions I would suggest they be worn to starting on the top row going from left to right:
1. Summer or spring garden parties as well as the occasional illustrated Easter sermon.
2. Your wedding, or any time you must go to a government office - they will take you seriously if you wear these.
3. Prom or your wedding reception.
4. These are your fancy, around the house slippers.
5. One for every work day + 1 bonus pair that is great for those important meetings.
6. For those footloose moments where you just have to dance. (the heel is not removable)
7. ORU Graduation to really show your school spirit.
8. Your first child's birth- comfortable, stylish, wipeable, and they will blend-in.
9. For any time you meet the emperor in his new clothes.
I wish I could find that specific clip from the episode, but since I can't, here is a link to watch the full episode.