Don't: Buy a bra solely because it looks cute.

Well, if you've got some extra money set aside in your bra budget, this is fine. But if you're out because you need a versatile bra you can wear with a tight white t-shirt, workday suit or layer under a slinky dress, then that hot pink lacy number with no cups or liners probably is not the best bet. Remember, this bra will have to go under whatever you have on, while still staying inconspicuous. So unless you want to wear your new bra the few times a year you pull on that thick wool sweater, you may want to reconsider your selection.

Do: Gather several bras in a couple styles you like, in your designated size.

While you don't want to overwhelm yourself, you also don't want to be repeatedly shuffling through dressing room lines every time you try on a bra that doesn't fit. Even bras of the same size may fit differently from style to style. For instance, a full coverage bra is going to need to hold more of your breast than a demi, which just covers 3/4 of your chest. If you have a specific color or style in mind, all the better. If not, just grab a variety in your size, to ensure you'll find something you like.