To start, we’re going to cut out the shape for the bottom of our apron. First, measure as far around your waist as you want the apron to wrap. I’d recommend it wrap a little towards the back for a more flattering fit. Take that measurement, and add about 6 inches to it since we’re going to gather the top, and we’ll lose some length. Now measure how long you want your apron to be.
Take your fabric, and fold it in half. Measure out half of your waist measurement (because it’s folded) and the desired length down. If you want it to flare out a bit at the bottom, angle it out a bit from the waist measurement, and then cut it at a slight curve towards the middle, as shown.