1. If you have bad luck recently, put your shoes outside the door, which means "ward off evil spirits" and seek good luck.
2. If there is no big problem. Put the unused shoes in the box, which means harmony at home.
3. If you usually wear shoes when you go out, the shoes should be outward (not indoors), indicating that there is hope for the future.
You should choose one of the above three according to the situation.