Trace a copy of your contoured bodice up to hipline, then shorten it drawing the new hemline:
- straight, 4 to 5cm below waistline on back
- slightly curved and slanted downwards on front, from 4 to 5cm below waist on side seam (match to back measurement) to 10 or 12cm below it in center front.
Then on front draw underbust dart (drop from bust point as half of bust distance minus 1 to 1,5cm) and widen waist dart so that it it 3cm at underbust. Shape waist dart as a rocket 😉