Also pull the bottom geometry out. That will be my chin.
Your chin may require something radically different.


Here's a look at the side view.
Not very head-like.


That's better.
As you can see, I select whole point strings to better form them into the desired contour.


This is what I look like in the perspective window - but not for long.



More geometry!

I select my face(s) and smooth-shift them out.

If you're not happy with the contours, correct them now. Every polygon you make is a polygon that you will have to tweak - repeatedly.


Smooth Shift.
This tool is your friend.
Select two or more polys in a row, than saw all the polys in that row in two!
Switch to point mode and all the newly generated points are selected.


Grab the bottom polys and shift them downward. This is the neck.


By stretching and tweaking the points of selected polygons between each shift, you can quickly create form close to what you want.

Don't worry about getting perfection right off the bat. The model has to work as a whole, so it's oftern wiser to come back and rework areas after neighboring areas have been worked along.