Summarize this article in one sentence.
Origami paper already comes in the shape of a square, but you can make your own square with regular paper. To create a square, take a piece of paper and fold the top corner over to the opposite side of the paper, until the top edge of the paper is in line with the side of the paper. This will create a triangle. Then, cut around the triangle shape and open it up. You should have a square. make a square from normal letter-sized paper  When folding the top corner, you should be creating a diagonal at the top of the paper. You don't want to fold the top corner over to the other top corner as this will just create a rectangle. You can use any color for this project -- choose a color that you want for your dog.

Summary:
Use origami paper or make a square.