Trace back and front separate to hipline.

On both pieces, drop 2 to 4cm from armpit point.

Draw the new back neckline squaring all the way to center back. On front, draw the new neckline dropping 12 to 15cm from center front neckline and going to shoulder line roughly halfway. Then measure 4 to 5cm for shoulder strap width and draw new armhole to previously found new armpit point.

Measure 1cm along new front neckline and draw an additional dart to bust point (this helps bodice sit closer to chest).

Measure matching distances on back shoulder line and draw shoulder strap (make sure width is consistent) to new back neckline.

Cut through new front neckline and new dart line.

On back, discard 2cm from center at waist and blend to zero at nape point. This makes corset smaller than natural waist, cinching it a bit. If you prefer corset to be more comfortable, reduce dart to balance the taken volume.

Make sure back neckline starts at right angle from new center back. Cut through all back lines.

You get:

• back shoulder strap
• back bodice
• front bodice.

On front bodice, draw 3 panel lines:

• measure 4cm along new neckline from center front and 3cm along hipline, connect them with a straight line to find 1st panel
• from first dart line at waist, draw a slanted line to hemline (parallel to 1st panel line)
• measure 5 to 6cm along armhole from armpit point, then draw the slanted line to hemline.