Bust - With a bra on and your clothes off, measure around the fullest part of bust and under the arms. Keep the tape straight across your back.
Waist - While in a relaxed position, measure around the narrowest part of your natural waist. The tape should go to this area if you softly tug at each end a couple of times.
Hip - Stand with your legs and feet together and measure around the fullest part of your bottom.