You will need: denim; fusing; a zipper.
Attention! Fabric consumption varies depending on the size of garment. First of all, print out paper patterns and lay them out at the width of fabric/ knit you plan to use, to see how much fabric you will need.
When sewing the garment, pay attention to notches- they must coincide.
From the basic fabric:
1. Gusset - 6 details
2. Facing - 4 details
1. Apply the fusing to wrong side of facings.
2. Serge closure edges in left side gusset. Sew gussets' side edges leaving closure slit unstitched. Serge joining seams and press them.
3. Sew side edges of facings and press seams apart. Serge facings' outer edges.
4. Sew the zipper in. Sew facing to garment upper edge. Overstitch facing upper edge with lower edge. Edgstitch facing, stopping at 3 cm (1-3/16") from end. Fold lower facing side edges under and sew them to side seam allowance. Topstitch lower serged edge of facing on seam joining upper facing.
5. Serge garment lower edge, press and topstitch.