Things You'll Need
T-shirt at least 2 to 3 sizes larger than the size you normally wear
T-shirt that is your size
Cloth marker/tailor’s chalk
Hand-stitching machine/sewing kit
Round object the size of a small place
Fabric fastening tape
For those who thought onesies were only for babies, think again. Adults too can and do wear onesies. Adult onesies are worn for comfort and convenience, as sleepwear in place of pajamas for both men and women. In addition, adult onesies make it more convenient for those who suffer from incontinence to wear and change adult diapers when necessary.
Reverse the oversized T-shirt and lay it flat on the table, face down. Smooth out all wrinkles. Take the fitting T-shirt and lay it over the oversized one. Align carefully along the shoulder line on the top. Smooth wrinkles again. Turn the T-shirt on the other side and repeat the process.
Mark the outline of the smaller T-shirt over the larger one with tailor's chalk from the armpit downwards. Use your round object to mark the armpit from the line that started from the armpit; this will be parallel to the armpit line of the larger T-shirt.
Put pins about 2 inches away from the line you have just drawn. Turn the T-shirt inside out and wear it. Mark the place where the split of the legs should be with the help of the chalk.
Sew along the drawn line, leaving about 2 inches of space. At the leg split, stitch a reinforcing line.
Cut along the seams and remove the excess T-shirt. Fold the T-shirt in half lengthwise. From the center outwards leave about 4 inches for the crotch and mark the point 4 inches from the center.
Open the T-shirt and fold the lower corners of the T-shirt upwards so the lower part looks like a panty. Fix with pins along that line.
Sew along the pinned line. Fold and again sew to form a hem along the sides. After stitching on all four sides (back and front), cut away the excess triangles (corners).
Turn the bottom margins of the T-shirt and attach the fabric fastening tape to it with stitching.