Gather twine or string, decorative paper, scissors, a ruler, a straight edge and craft glue for the project.
With the ruler and a pencil, mark the height of the pennant on the decorative paper. Draw a straight line across the length of the paper. Measure and trim multiple strips of paper that are the same height as the pennant.
Determine the width of the pennant at its base. If the pennant is 4 inches wide, make a pencil mark every 4 inches along the bottom edge of the strips. On the top edge of the strips, start 2 inches from the side, and make a mark every 4 inches.
Starting at the bottom corner of the paper strip, cut to the first mark along the top edge, and cut down to the next mark on the bottom edge. Continue cutting triangles from all of the strips.
Cut a piece of string or twine to the desired length of the banner. Fold down the base of each triangle half of an inch, and trim off the corners. Add a few dots of craft glue to the fold, then fold the base over the string and press down the paper. Continue gluing pennants along the length of the banner.