Seal the top on with duct tape. Tell what each room is used for. Write a list of all the objects in your bedroom. As you select artifacts to put into your time capsule, consider their size. Use acid-free paper.
Newspapers have a very high level of acid and deteriorate quickly.
You can find acid-free paper in most art supply or craft stores. Put small artifacts in acid-free envelopes or clear plastic kitchen bags. Plastic, glass, metal or rubber objects need no extra protection. Be sure to include a list of what you put in the time capsule. Describe the artifact and why you thought it should be in the time capsule.