Measure your shoe size Follow the steps below below your example. Make sure to do this during the day or on a specific and appropriate basis (feet usually swell during the day). Step 1. Place a piece of blank paper under the foundation. Stand properly and make your heel touch the wall loudly. Step 2 Ask someone to mark the end of your toe and the back of your heel on the spot with a pen or pencil. Then measure a long length from the heel to the ball of the foot. Step 3 Repeat the same step on the foot and then make sure of the length of the feet and then choose the appropriate size