Step 1: First
You need a polystyrene head then put layers of modelling clay on your head.
Now sculpt your mask mold by using photos as a guide.
Step 2: Now
You do your first layer of latex on your mold you will need to do about 10-15 think layers u can do as many as you need
Step 3: Finally
Peel off the mask from the clay by cutting up the back it should come off easily but if not use Vaseline or powder to loosen the grip.
Once your mask is to your standards then you can paint or just leave it.
I add some eyes from an old toy which worked quite well but you could use teddy eyes or something. To attach use hot glue be careful its hot!