Bust:Bust measurements are taken at the fullest part of your bust. Measure around the fullest part of the bust and over the shoulder blades - keep the tape level and straight.
Waist:Waist measurements are taken around the narrowest part of your waist between your ribcage and hips. Measure around your natural waist, that is where the bend is at your side. (If you stand in front of a mirror and bend to the side the crease that forms indicates your natural waistline).
Hips:Hip measurements are taken around the widest part of your buttocks. Measure around the fullest part of the hips, while standing naturally.