First of all draw a circle.
Now draw these lines it'll help you to locate the area to draw eyes, nose and mouth.
Now start Drawing Sukuna's Face beneath the circle.
Now draw ears and draw these two lines beneath the ear to draw his neck.
Now draw Sukuna's hair above the circle as you can see in the picture above.
Now draw eyes and nose. Sukuna has the same eyes as Itadori Yuji . Because Itadori Yuji is Sukuna's Host.