If you use the size chart and are still in doubt, use your average pant size.
Do not order a smaller size with the thought that you will have more control. If the fit is improper, you will not look your best. If all measurements fit within a particular size, except your torso, order the next size up.
How To Measure Bust: Measure fullest part of bust, keeping tape parallel to the floor.
Waist: Keep one finger between tape and your body. Measure a little below your natural waist, where you actually wear your clothes.
Hip: Stand with heels together. Measure across the fullest part, keeping tape parallel to floor.
Boots: When buying boots, it is sometimes necessary to buy one size up from your regular shoe size due to the enclosed toe.