-Machine baste(longer stitch length) the seam where the zipper is to be placed. Backstitch at the end of basting and change the stitch length to a regular stitch length(2.5 or 3) -press the seam allowance open.
-unzip the zipper. Place the zipper with right side of the zipper to the seam allowance on one side of seam. Butt the teeth of zipper to the seam opening. -using a zipper foot, and regular stitch length stitch the zipper tape on one side of the zipper to the seam allowance only. (The needle should always be between the zipper teeth and the zipper foot.)the needle or the zipper foot may have to be repositioned to begin sewing. - Stitch from the bottom to the top of the zipper. This will secure the zipper in place
-Close the zipper. Spread the garment flat with the right side up. Make sure that zipper is in correct position. - mark the bottom stop of the zipper with a pin or fabric marker. - begin stitching at the bottom of the zipper ¼”from seam line. Backstitch to secure the thread. -Stitch across the bottom ½”(1/4” on each side of the seam). With the needle down raise the presser foot and turn the fabric, continue sewing ¼” from the basted seam along the side of the zipper. Begin again at the lower end, backstitch to secure the thread and stitch the other side of the zipper ¼” from basted seam. Remember that the needle should always be between the zipper teeth and zipper foot. -Remove the basting stitches.