To measure your bust, first; ensure you are not wearing a padded bra for a more accurate measurement. Relax arms at side and pull tape across fullest part of bust. Very important side note: your bra size is not your bust size.
Bend slightly to one side to create a natural crease of the waist, this will be the narrowest part of the waist. Measure across this point ensuring that the tape is not tight on the area being measured.
To measure hips, stand straight with both feet together. Measure around the fullest part of rear and hips, ensuring that the tape crosses the hips bones.
For all measurements ensure that the tape is not tight or loose. A relaxed measurement will yield the most accurate measurements.