Trace a copy of back and front bodice to hipline, then:
- widen neckline by measuring 2 to 3cm from high shoulder point along shoulder line
- redraw back neckline keeping original nape point or dropping it by 1 to 2cm
- change front neckline giving it more of a U shape (you can drop 11 to 17cm in center front)
- draw the neckband 8 to 10cm wide from center back to front. Try to make the line passing through bust point.