Cut lengths of crepe paper into streamers that are twice as long as you want the pom-poms to be. For instance, if you want the pom-poms to be 4 inches, cut the streamers into 8-inch lengths. You will need at least 10 full streamers for a good-sized pom-pom. You can always add more or subtract some if you aren't happy with the fullness.
Cut the streamers down the center lengthwise to make the pom-pom strands thinner. If you want thicker strands, you do not need to cut the streamers in half lengthwise.
Fold the streamers in half so they are the proper length for your pom-pom. Bunch all of the streamers together to form a puffy pom-pom.
Tape the bunched ends of the streamers one end of a wooden dowel or unsharpened pencil. Overlap the streamers with the dowel or pencil by about 1/2 inch for a better hold.