Naomi: The Essential in White

Your band should be snug and stay parallel to the floor. If you feel your band riding up on the tightest hook, it's time to go down a band size. You should be able to fit the width of two fingers comfortably underneath the band at the back—if it stretches more, we recommend trying a smaller band size.

Your breasts should fill out the bra cups but should not spill over (aka, the dreaded quad-boob effect). If you bra cups are puckering, you may need a smaller cup size. Also—everyone has breasts of different sizes! If one cup fits well and one is puckering, one of your breasts may be smaller than the other. In this case, it is best to fit your largest breast and use an insert to fill in the other cup.

Your straps should be comfortable and should only carry about 20% of your breast weight. If your straps are digging into your shoulders, try loosening them.