More seams equals more support

When it come to cups in bras, as a general rule (though not going crazy) the more seams you have the better support and fit the cup with be. The most popular of the larger cup, is a three-piece-cup. With two-pieces making up the lower cup and a seam running across the cup for the top cup. The more curve you have on these seams, the more volume will be projected.  

The following brands use the three-piece-cup. 

CLAUDETTE

CLAUDETTE

MISS MANDALAY

MISS MANDALAY

FREYA

FREYA

CURVY KATE

CURVY KATE

Top tip: Apex of the bra

For those wanting to extend their lingerie range D-cup or above, remember when grading the apex of the bra (where the strap meets the cup) you need to bring in the apex, not make it bigger like the rest of the cup.

Bigger boobs need more of a centre pull (strap needs to be more in line with the nipple) so the straps don't dig into the underarm and isn't worn at an angle on the shoulder.