One of the most common errors in choosing bras for plus size women is picking one with cups sizes that are too small and a band size that is too big. This happens because a large number of bra styles do not have larger cup styles. However, it is important to buy a plus size bra that fits your specific measurements only.
There are a number of retailers, specifically online, that cater to large bra sizes. The important thing is to get the right fit -- even if you must take extra steps to do so.