To make a Christmas tree napkin, you'll need a square napkin, a few pipe cleaners, and some craft supplies like glue, scissors, and green and red paper. Start by folding the napkin diagonally to form a triangle. Next, fold the triangle in half again to make a smaller triangle. Then, use a pipe cleaner to secure the triangle at the top of the napkin. Use green paper to create a tree trunk and glue it to the bottom of the napkin. Add ornaments and decorations using red paper and glue. Finally, use scissors to trim any excess paper and create a festive Christmas tree napkin.