1 Download the template, then print and follow the cutting guide. With right sides together, matching the side and centre back edges, pin and sew the bodice backs to the trouser backs at the waist. Trim the seam, neaten the edges and press downwards.

2 Insert the concealed zip, then align the teeth with the 1.5cm seam allowance, pin and stitch in place. Position the teeth into the groove of the foot at the beginning of the stitching, leaving 5cm of the zip unsewn at the base. Match the waist seams, then stitch the centre back trouser seam from the zip base to the inside leg using a zipper foot. Trim this part of the seam and neaten the edges. Cut the seam to the stitching line at the base of the zip, then press to one side.

3 Create the front bodice darts and press downwards. Pin and stitch the centre front seam of the trouser, then trim the seam allowance, neaten the edge and press to one side. Stitch the pocket facings to the side edge of the trouser fronts. Trim the seam and press the facing to the wrong side of the trouser front, then topstitch close to the pocket edge.

4 Pin and sew the pocket to the facing, leaving the side seam unstitched, then neaten the edge. Press the assembled pocket and trouser, then pin the pockets in place from the waist edge to the side seam. Join the bodice and trouser fronts at the waist edge, right sides together, ensuring the centre of the bodice is aligned with the front seam of the trouser.

5 Trim the seam, neaten the edge and press 1.5cm downwards. Pin the jumpsuit front to the back at the side seams, making sure the waist matches, then stitch. Trim the seam, neaten the edge and press towards the back. Pin and stitch the inside leg seam from the hem of one leg to the hem of the other. Match the centre back and centre front trouser seams and notches. Trim and neaten the seam, then press towards the back.

6 Fold each strap in half, right side inwards, and stitch with a 1cm seam allowance. Turn to the right side and press the seam to the middle of the strap. Position the straps so the edge is 1.5cm from the arm edge of the back bodice, and the right side of the strap is against the right side.

7 Pin and stitch the side seams of the front and back facings, right sides together, then press open. Neaten the edge of the facing and position it at the top of the front and back bodice, covering the straps at the back.

8 Make sure the middle of the facing is aligned with the centre of the front bodice, the facing side seams and the bodice. Sew all the way around, leaving the top front unstitched. Sew across the top of the front bodice, clip the curves, then trim the seam and any excess fabric. Under-stitch as far as possible on the facing, then turn it to the inside of the jumpsuit and press.

9 Turn the back facing edge inside and handstitch it to the zipper tape at the centre back, making sure the top edges are level. Handstitch the facing to the side seams under the armhole. Join the two sash pieces together and press open a 1cm seam. Fold the sash in half lengthways and stitch, leaving a gap in the middle for turning.

10 At the bottom edge, stitch across at an angle. Turn the sash right side out and press with the seam on the edge. Handstitch the gap closed. Try on the jumpsuit to check its length, then turn up the hems to the length desired and press. Fold under the raw edges and stitch close to the fold.