Large bust and armhole 'gaposis.'

There appears to be an inverse relationship between a large bust and the size of the front armscye, i.e. armhole: the larger the bust, the smaller the relative size of the armhole. The paper pattern must be altered before any fabric cutting is done because a too-large armhole produces a gap that defies alteration options.

It helps to think in terms of fitting the armhole--not the bust. This is, of course, what you are actually doing and it is done by folding the excess out of the armscye via a pie-shaped angle that terminates at the apex of the bust. This pie-shaped folded excess will cause a 2-d pattern to take 3-d shape. To flatten the pattern again, select a bodice seam (other than the armhole seam, of course) and slash a line from the selected seam so the slash goes in the direction of the apex of the bust.

Voila! This pivots the armhole excess--which has become a dart--to a more pleasing origin. Commonly these darts are designed to originate from the side seam of the bodice. However, the origin can be from the shoulder seam, a center front seam, etc. They can also be incorporated into
waist-fitting darts or can even be disguised in seams such as in princess line styles.