lady-amaranthine answered:
Go to a good lingerie store/department and get measured! Also try different styles - some will look a lot better for your body than others even if the back and cup size are the same so don’t assume they’ll always fit without trying. Never wear the bra on the tighter hooks until you’ve owned it a good while - it should fit on the loosest hook when you buy it and then pull it tighter as it stretches with time. Lift your titties around inside the cups so they sit inside comfortably, don’t be afraid to get in there and really hike them around. Make sure if you get an underwired bra that the central section is as flat as possible against your chest, that means your getting the best support and fit. If you want to feel super supported get a fuller cup instead of a plunge