Go through this checklist and you are good to go!
CUPS – Your breasts should fill the cups completely, without spilling over the topof the bra or under your arms. Spillage means you need a larger cup size. Wrinkly fabric in the cups means the bra is too large or that it’s the wrong shape for you.
STRAPS – They should sit straight and flat, without digging in or sliding. Straps should be re-adjusted after each wear.
BAND – To anchor a brassiere properly, the band, when fastened, must make a prefect circle around your rib cage. The band should be snug but you should still be able to fit a finger underneath.
UNDERWIRE – They should lie flat against the chest and never sit on top of the breast tissue itself.
CENTRE FRONT – The fabric should sit flat against your chest.
CLOSURE – The closure must lie flat without pulling. Front closure can’t accommodate slight weight gain or bloating like the back closure can.
Source: Secret of style