Choose the zipper type and length (invisible, separating, centered, or regular)
Measure the opening length and add any needed seam/turn allowances
Pre-wash and press your fabric; interface if required
Mark the zipper placement on the fabric using tailor’s chalk or a washable marker
Finish the seam allowances (zigzag/serge) if fabric frays
For a regular zipper, baste the zipper teeth to the fabric right sides together along the marked line
For an invisible zipper, baste the zipper to the fabric with the zipper tape face down, teeth aligned with the seam line, using the presser foot for invisible zippers
Pin or baste the second side of the zipper in place
Sew slowly with the correct presser foot, keeping the zipper teeth aligned and avoiding sewing over the zipper stops
Backstitch at the start and end of each seam
Remove basting threads
Press the seams carefully (use a press cloth if needed)
Close the zipper; check alignment and evenness
Trim seam allowances and corners if needed (avoid cutting near stitching)
Sew the remaining seam(s) around the zipper opening to close the garment/project
Press the zipper area again, opening the zipper slightly while pressing if possible
Topstitch if desired (edge-stitch/zipper topstitch) on the right side for a regular zipper
For invisible zippers, press the seam allowances and topstitch lightly if desired
Secure zipper ends (bar tacks or short backstitches) if your pattern requires it
Final press and clean up loose threads