Let’s draft together the pattern of this dress.
Start by drafting a basic block with darts and zero ease allowance.
Mirror the front for the asymmetrical style.
Draw the neckline and widen the shoulder dart by 1 cm at it, then draw the bust and waist cuts as you see in the photo.
On the front skirt, reduce at the hem a couple of cm from each side, draw the flounce and the slit line.
On the back, draw the neckline, discard the waist dart half from the center and half from the side seam, draw the skirt line and the back part of the flounce.
Trace the separate light blue pieces (back and front flounces/rouches) together mirroring the separate pieces.
Keep the notches to separate the segments and redraw the outer shape where needed.
Trace the separate pieces: center back, front upper bodice (closing the shoulder darts), lower front, side front panel skirt, flounce.
How to sew it: first create the flounce pleats, overlap the flounce to the side front panel of the skirt, then sew the block to the bodice and center front.