First I took in the dress at the sides, a fairly standard alteration. Then we started making muslin test bodices to try out different styles. The following pictures show the two main cuts that we experimented with:
A wide ballet neckline with a little cap shoulder....
....or a wider shoulder with a deep, slightly sweetheart-shaped neckline.
After settling on the first option I got to work perfecting the fit of the muslin, front and back.