To make a Christmas tree from a napkin, you will need a square-shaped napkin, a pair of scissors, and a small piece of string. First, fold the napkin in half to create a triangle shape. Then, fold one corner of the triangle down to create a smaller triangle. Repeat this process with the other corner of the triangle to create an even smaller triangle. Once you have created a tiny triangle, tie the piece of string around the base of the triangle to secure it in place. Then, use the scissors to trim the edges of the triangle to create a pointed shape that resembles a Christmas tree.