Materials: 1 large T-shirt, preferably all-cotton, ironed; a sleeveless well-fitting T-shirt to use as a pattern; sewing machine, straight pins
1. Fold the larger shirt in half and mark the center line with pins. (The shirt should remain right-side out.) Unfold the shirt, and align the underarms of the smaller shirt with the larger shirt and trace the outline with chalk or a pen, depending on the color of the larger shirt.
2. Remove the smaller shirt and pin the front and back of the larger shirt together (it doesn’t matter where you place the pins). Sew the front and back of the larger shirt together along the marked shoulder lines, reverse stitching 1/2 inch at each edge for reinforcement. Do not sew across from one shoulder to the other — it will need a neck opening.
3. Cut off the original shoulder seams from both sides of the shirt. Mark at 1-inch intervals along the top of the original shoulder seams from neck to outer edge. Cut through both layers of fabric down to about 1/8 inch above the new shoulders.
4. Create a new neckline by cutting in a scooped line between the shoulder seams. Cut off the sleeves of the shirt, following the lines you traced. Starting at the underarm, sew shirt together along the side lines; make sure to end the stitches at the bottom of the marked shirt lines.
5. To make “corset hooks”: Starting under each arm and ending at the point where the new side seam ends, mark 1-inch segments down the side of the shirt. Cut the front and back of the shirt at the inch marks, from the old outer seam to the new sewn seam, being careful not to cut into your new stitches. This will create loops at the side of the shirt. Repeat on the other side.
6. To make the “corset laces”: You will be cutting a one-piece spiral strip. Start on the right-hand side, beneath the horizontal cuts and the side seam: Make 1-inch marks down the original side of the shirt. On the left-hand side, beneath the horizontal cuts and the side seam, make a mark that is only 1/2 inch down. Continuing from there, make marks at 1-inch intervals down the original side seam.
7. Using chalk or a pen, and a ruler, draw diagonal lines to connect the marks you just made. Cut a 1/4-inch notch into the side of the shirt at each mark, cutting through both layers of fabric.
8. Flip the shirt over. Draw diagonal lines to connect the notches you just cut, making sure that the new lines match up with the lines already drawn on the front of the shirt. (These diagonal lines will slant in the same direction as the ones in the front.)
9. Remove any pins from the shirt bottom. Carefully cut the fabric in one continuous line, first following the spiral line drawn across the front fabric, then across the back fabric, then around again, until you have reached the bottom edge of the shirt. This will produce a long, 1-inch-wide strip hanging at one end from the bottom of the shirt. (Adrian Buckmaster)
10. Thread the loose end of the strip in a zigzag through the shirt’s “corset hooks.” Start at the bottom loop across from where the strip was attached and weave it through every other loop on either side of the shirt. When you get to the top of the loops, weave the strip straight across to the other side and then down, zigzagging through the remaining empty loops. (Adrian Buckmaster)
11. Try on the shirt and adjust the width of the zigzags to your size. When you’re sure where to end the strip (it will be much longer than you need), tie or sew it into place. Knot the ties at the shoulders as desired. (Adrian Buckmaster)