This may not be such a great idea, Marie, because (1) a picture is worth a thousand words, and (2) I’m a renegade seamstress who doesn’t do things by the book.
I’d start with something very cheap from the second-hand store to practice on. Of course you’ll become a perfectionist in time, but remember that it only has to be functional to be worn with a long shirt and low belt. In that case, don’t bother making belt loops on the garment, as they will only add bulk underneath.
Materials: unbleached, pre-shrunk (washed) muslin for interfacing; preshrunk woven cotton for facing; 7-inch zipper that matches your garment; large paper (newspaper roll ends work great.) The facing fabric will not be seen and can be any print or color you like.
• Carefully remove the existing waistband and zipper. Discard zipper and save waistband for belt loops.
• Try the garment on in front of a mirror deciding exactly where you want the waistline to be and roughly draw circumference with chalk. A waistline where the back is two to three inches higher than the front supports natural spinal curvature.
• Place garment on tabletop and clean up line with a ruler, measuring evenly so that the sides are balanced. Add 5/8-inch seam allowance and draw new line. Cut along this line.
• Replace the zipper. Don’t worry if the length of the opening is shorter than the zipper, because you can cut the zipper to any size and whipstitch a new stop for it.
• Press the seam allowances flat on either side of the opening. With contrasting, double-strand thread, on OUTSIDE, carefully baste the opening closed with long whipstitches.
• On the INSIDE lay the zipper along the opening, making sure the zipper-pull is facing down and all upper edges are even. Pin the zipper into place.
• On OUTSIDE, sew in zipper. This can be either machine-stitched with a zipper foot, or carefully sewn in by hand. Sew down the left side first, top-to-bottom, back stitching at the end. Sew down the right side and then pivot across the zipper to meet stitching on other side. Remove contrast basting thread.
• Place garment on top of paper to draw pattern for facing. Depending on where the opening for the zipper is, you will draw either:
1. One front and one back facing, which will open on the side;
2. One front and two back facings, which will open at the back;
3. Two front and one back facings, which will open in the front.
• Trace along the upper edge of garment to obtain one of the above groupings of facings, being sure to add 5/8-inch seam allowance to the sides of each pattern piece. With a ruler, measure 3 inches in length all along the waistline, so that the finished facing pattern pieces are 3 inches long by however many inches around.
• Sew the sides of the facings together with a 5/8-inch seam. Press seam(s) open.
• Iron your interfacing fabric. Lay the circular facing RIGHT SIDE UP on interfacing fabric. You will want to place it along the long grain of the interfacing fabric and not diagonally. Pin and cut out. Sew these two pieces together just as you have them pinned, using a straight stitch at the top and side edges, and a finishing or zig-zag stitch all along the bottom edge.
• Pin the facing to garment, RIGHT SIDES TOGETHER (interfacing on the outside.)
• Sew facing to garment along upper edge using a 5/8-inch seam.
• Trim and grade the seam allowances. This means trim the garment allowance to about 3/8-inch and the facing allowance to about 1/4-inch. This makes the seam lay flat. Press seam allowances toward facing. Turn in facing ends and press, then turn entire facing to inside and press flat.
• Tack facing into place at sides and top stitch all along top edge.
• If desired and if you were able to save enough garment fabric, make belt loops. Cut a fabric strip 18 inches by 1¼ inches. Press under ¼ inch on both long edges. Fold in half, press, and pin. Sew strip together using a locking stitch.
• Cut finished strip into 4 4½-inch pieces.
• Decide where you want loops, measure evenly, mark with chalk, and sew into place with zig-zag stitch. Press loops flat and straight-stitch across top and bottom edges.
