Fold a rectangular piece of paper in half, making a long, thin rectangle.
Make a series of cuts (about a dozen or more) along the fold line. Don't cut all the way to the edge of the paper.
Unfold the paper. Glue or staple the short edges of the paper together.
Cut a strip of paper 6 inches long and 1/2 inch wide. Glue or staple this strip of paper across one end of the lantern - this will be the handle of the lantern.
Optional: Make a lot of lanterns and string them along a length of yarn. Decorate your room!