Download free PDF Step by step guide 1.Cut 2 pieces of batting using tail fin template.2.Tape template halves together (A to A and B to B). Cut 2 pieces of fabric using the whole mermaid tail template.3.Iron the batting onto the lower end of the tail.4.Sew the 2 pieces together (0.5 cm seam allowance). Trim corners. Turn to right side. Press.5.Overlock the side seams and top.6.Sew stitching onto the tail. See template.7.Cut a 20 cm length of elastic for the large tail and a 15 cm length for the small tail. Sew elastic to form a circle.8.Fold fabric to the wrong side at the top. Sew a drawstring hem on the mermaid tail with the elastic inside it.