>>7789733
Do the circle like this. Do the vertical division to the left (or to the direction the face is looking) instead of the exact center. Same with the horizontal line, do it slightly lower than the center. This horzontal line will be the most usefull, use it as the bottom of the eyes, where the nose is and also where the top part of the ear and the head connects.
The vertical line should also overshoot outisde of the circle to show where the chin will go.