Cut out 2 circular cardboard pieces with the desired diameter. Cut a big hole in the middle and make 1 cut across the pieces. Place the 2 pieces against each other and wind the yarn round as shown in the illustration. The more yarn, the denser the pompon. Cut the threads between the 2 pieces, be careful not to pull out the threads! Use a double thread to tighten round the middle of the threads between the 2 pieces. Pull tight and sew. If the pompon is a little uneven, adjust the lengths of the yarn ends.