Step 1
Trace a copy of back and front, then draw underbust line.
Widen waist dart at underbust so that it is 3cm at it all the way to the waist.
Extend center front 4 to 6cm below waistline, then draw a slanted hemline to waist level at side seam.
Draw a similar slanted line that starts in center front 4 to 6cm above underbust line, passes through dart at underbust and ens at side seam below underbust line.