Sideless shirts are popular among people who want a relaxed look. You don't have to be daring to wear a sideless shirt, just pair it with a tank top and you'll be totally styling and you won't have to worry about anything popping out that should stay hidden. Update your wardrobe and go green at the same time by recycling a plain T-shirt into a sexy sideless shirt.
Cut the neckline off your T-shirt. Follow the seam line and cut about ½-inch beyond it.
Lay the T-shirt flat and measure up 3-inches from the bottom and mark with a dash on the right and left sides of the shirt.
Cut from the shoulders down to the dash 3-inches from the bottom removing the sleeves and sides of the shirt.
Cut a strip from one of the sleeves you cut off then cut it in half so you have a long strip rather than a tube. Depending on how big the sleeves were this could be a narrow strip or very wide. You will be using this to tie the back of your shirt to give it some shape.
Put on your sideless shirt and pinch the back fabric together at your waist however tight or loose you like. Tie the sleeve strip around the back where you've pinched the fabric together.