My roommate taught me how to do a self examination..
Bra's
Well I wear a 36D bra, I learnt that a good bra is important. I prefer under wire as I personally feel it gives better support. I love a good push up bra, as it shows off my girls

having bigger breasts I rarely go bra-less.. when I wear strappy tops, I try buy the one with support build in.. or I try and wear a strapless bra. Going bra-less a lot can cause your breasts to sag and will give you back problems
When exercising wear a sports bra, they support you well, especially when jogging..
Bra sizing can be tricky. I went to professional fitting.. A bra must not dig into you or breasts must not overflow the cup. The clasp at the back, should fit roughly half way down you back. I barely feel my bras when wearing them.