Boobies Deserve Happiness
I know I've said this before, but if you wear a bra, get thee to a bra fitting specialist right this very moment.
I so mean it and don't want to hear any excuses.
I know it's weird and uncomfortable and... weird. But treat it like a doctor's appointment. A checkup for your girls that doesn't involve squeezing them between two metal plates. A checkup that involves lace. And a tape measure.
Go to a fancy place (overheard in the dressing room next to mine while trying on a bra that was individually hand made in France with the sweat, blood, and tears of sweatshop children: "A bra is important to me! I'll pay up to $30 for a good bra!" Which, um, just to clarify: WalMart doesn't count for this exercise.) where the fitter knows how to handle a pair of breasts. She will know what size you should be and what styles would look best on you.
Let her pick out a huge pile of bras for you and then? Try them all on. Even if it takes you two hours. Even if they are all in size 34GINORMOUS and are bigger than the state of Texas (these are Alaskan boobs, dammit!).
It's best if she helps you try them on, because she knows where to hook it and how to adjust it and will tell you when it doesn't fit right, and you don't stand alone in the dressing room for 15 minutes trying to wiggle the band of a strapless up to where it really needs to go to support your GINORMOUS rack even though the band won't go any higher and OH MY GOD MY SHOULDER JUST DISLOCATED.
She will know. Trust her.
If she makes you uncomfortable during the fitting (and I mean more uncomfortable than an I Am Standing In A Tiny Room Half Naked While A Stranger Pokes At My Breasts kind of way), then leave. Don't buy anything you don't love or can't afford. Don't let her pressure you into anything.
If she makes you uncomfortable from the get go, don't lock yourself in a tiny room with her and disrobe.
Which, really, is just a great Life Lesson you should have learned in Junior High: If you don't like someone, don't let them get your shirt off.