Wrap the measuring tape around the trunk at the bust, going over the breasts. Do not let the measuring tape slid down at the back.
Wrap the measuring tape aroung the waist (which is approximately near the navel, below the ribs)
Wrap the measuring tape around the widest part of the hips.
You should always wash it by hand, let it soak and rinse. Use cold water and no kind of bleacher. You should never machine-wash them or, even worse, put them in the dryer. Remember that the fibers of technological lingerie will last much longer if washed properly.