Start from a fitted block with darts, full front and back for the asymmetric neckline.

Draw the new neckline and armhole (see left and right marked in two different colors).

Trace a copy of right front, close the shoulder dart and open its volume into the waist one.

Trace a copy of left ftony and draw the slanted slash lines for dart manipulation.

Cut through these lines.

Close the shoulder dart and redraw the whole piece.

Mark the  pleats at the waist (where you see the blue arrow, above letter B).

Then, draw the new slash lines:

• one from the shoulder downward
• one across the opposite edge at the waist.