Start from a basic block with darts and appropriate ease allowance.
On center front, lower 8-10cm and start drawing the line that will separate bodice and skirt. Keep it slanted, slightly rounded until you come on the side seam a couple of cm above the waist.
On the back, finish drawing the line from the same point on the side seam merging to the natural waist around the dart.
Square down from the apex of the darts and divide the skirt with slash lines to -later- add volume.