To measure an accurate band size, wrap a measuring tape tightly around your rib cage and add 5 inches.
Measure loosely around the fullest part of your bust and subtract your band size. 1" corresponds to A cup, 2" to B cup and so forth.
Look for lightly lined bras with contouring or an underwire to help define your silhouette.
Improve support by selecting a bra with wider straps, underbands and firm fabric construction.