1. Creating a foam head
For Savoy I used foam for the head construction.

First I got myself a styrofoam head as support. Then I cut the foam in stripes with an electric knife, and started building the basic form (I used hot glue). Step by step. Always check the symmetrie.

2. The jaw
Click on the left picture to see the drawing how it works.

I used a perforated wire and a normal one to make the joint (1). I have an additional strip of velcro under my chin (3) which will open the jaw when I open my mouth, the spring will make it close again. For protection I used mesh (4).

3. The fan / ventilation
I install my fans in the nose, blowing the hot air out of the head (not blowing fresh air inside).

To attach the fan, I used mesh and cable straps (easy to open again if there is a damage). The fan is a little too big, but I wanted a good ventilation. The 2 battery packs are located outside in the foam of the cheeks.

4. Furring
You should not attach the fur before having installed all electronics, jaw, etc. Hot glue, etc. might damage the fur (I already started furring before because I was too impatient).

I started with the ears, then forehead, muzzle, cheeks, etc. You can also use transparent paper you cut out before as pattern before you start cutting the fur.
The white stripe isn't the final fur yet (I dyed it in the end). On the back side, the light blue cheek fur is only attached with 2 stripes of velcro (1), so that I can open it to get to the battery packs located underneath them.

I first used light blue colored sheep fur (from IKEA) for the stripe, but when you cut the whool, it will curl and look more like a carpet than fur. So I replaced it again. Don't forget to trim your fur! Shorter fur on the muzzle, ears, etc. will look much better than the complete fur on your head having the same length.

5. Details (eyes, nose, teeth)
There are plastic noses and jaws (from taxidermists) you can also use for your fursuit head. For Savoy, the plastic teeth (1) were too small, so I just did the teeth with white FIMO.

The nose I cut out of foam rubber and painted it with colored latex milk (from a LARP store) in several layers. Latex milk becomes transparent when dry, so you have to add red and white for getting pink.
The eyes are made of a transparent plastic hemisphere (from a decoration store). The whites are (meanwhile) a part of plastic cut out of a white kitchen bowl (at the beginning I used mesh, which also works, but which is perforated).

In the middle, there is a hole cut out and a piece of sunglasses glued behind. So my angle of view is a little smaller, but through the sunglasses I can see better than trough mesh. The pupils are drawn with acrylic colors (should be waterproof).

6. The finished head
Finally - the head is finished!

There were still many little things I changed with the time, like the fur of the light blue stripe, the whites of the eyes, etc.
I also wanted to make those 3D follow-me-eyes at the beginning, but it didn't really work, so I will try again next suit.