Here's the skull in close-up. I hope you can see that his forehead is a rectangle with two triangles of background at the top. Then there is a row with the eyes and a row with the nose.
Had to piece the jaw section separately so that it would be narrower than the rest of the head and I took two eensy-weensy triangles of background to round it out a bit at the bottom. I then put background on both sides of the jaw section and sewed all that to the top of the skull. Then added some background to both sides so that it would be wide enough to start adding the lower sections to.
It really isn't that hard - you just have to work your way through it step by step, just like with the letters.