We want the returned books, clothing, shoes or toys to be in a condition allowing for them to be uses as they have been used before. In addition, the items should be clean, dry, and in good physical condition - without holes or major damage.
Send shoes in pairs, clean, and with no significant wear and tear. You can tie or strap them together.
Fill the box as tightly as possible - put things together and place them in the package. The more stuff you can fit in one package, the better for the environment.