This is great for weekend sleep ins. If you want to not be disturbed, make this for your door. All it takes is toothpaste box, covered in paper, with the message of your choice. Then tape or staple a string to hand on your door.
If you have a lot of small boxes you can make this really useful organizer. I used boxes from a pack of cereal. First tape all the boxes together with the opening on top. Then cover all of them with paper. Decorate and cut a cardboard sign to tape to the front.