Create a Small Paper Book

A small 4-page book with cover and back pages can be very simply made. Its uses are multiple and surprising.

Steps

Hold your square piece of paper (must be square) so that there is a top, bottom, and two sides. In the following steps, there are horizontal and vertical folds. It does not matter which side is horizontal and which is vertical; just designate one as horizontal and one as vertical.
Fold paper in half vertically. Do not unfold.
Fold paper in half horizontally. Do not unfold.
Fold paper in half horizontally again. Unfold.
Fold paper in half vertically again. Unfold.
Holding the paper fold-side up, cut along the vertical line halfway across the paper, until it reaches the intersection of folds.
Separate bottom halves of paper, so that the closer half is facing you, and the farther half is pointing away.
Fold one half of the paper down, and turn it 180° so that it is now upside-down.
Fold all the edges together and make a book.