First trace a copy of front and back with darts up to hipline. Ease allowance at this stage is not very important, so just make sure it is more than 10cm at bust circumference.
Flare 5 to 8cm from side seam.
Draw two parallel lines to center front, one 1,5cm inwards and one 1,5cm outwards. The 3cm band that you just created is the button stand.