Measurements should be taken directly against your body.
BUST: Measure around the FULLEST part of your breasts while wearing your usual undergarments. (Tape measure should be straight and parallel to the floor).
WAIST: Measure at your natural waistline, at the SMALLEST part. (Stand up straight and be relaxed, don't suck in your tummy).
HIPS: With your feet together, measure below your waistline at the WIDEST part. (About 20cm below waistline).
OUTSIDE SEAM MEASUREMENT: Waist to hem edge. (Make sure you're standing up straight when recording this measurement).