Start tracing a copy of your contoured dress (=dress with darts and zero wearing ease) if your fabric has a little stretch. If your fabric has no stretch I suggest adding 2 to 3cm wearing ease at hips.

Then:

• adjust length to desired measurement
• highlight waistline that separates bodice and skirt
• on bodice, draw the new neckline: on front it is perpendicular to center front 7 to 9cm above it and extends up to 2cm before armhole, then curves down to armpit; on back, it starts from armpit, curves downwards slightly and ends in center back 3cm below armpit level
• draw panel lines on back bodice: divide back waistline (including dart width) by 4 and square up to neckline
• draw panel lines on front bodice: square from bust point up to neckline and down to waist (see the blue line here), then divide the section in between blue line to center front by 2,5 and square up from the points to neckline (green lines). This way you’ll end up with 5 panels total in center front.

A full explanation on corsets and much more is covered in our basic blocks course/module 2.

Still on front bodice, draw the additional panel line starting from the angle in between neckline and new armhole section. Curve slightly and end at waist halfway between original waist dart and side seam. This line is marked in red here.

Now work on skirt: reduce 2 to 3cm from side seams in the knee to hem section, then blend to zero at hips.

Trace skirt pieces separate.