First put your tank top on and pin (or mark with a water-soluble pencil) right above your hips.
Then trace around the tank top adding 1/2” or so, with the bottom ending where you pinned. Make sure you make the straps at least 2 inches wide because if you don’t they won’t cover your bra straps by the time you’re finished!
Make a front and back bodice piece. As you can see the back piece is not as low cut as the front.
Now all we have left to do is finish the bodice! Spray around the arms and neckline with starch and press the raw edge under.