My inspiration came from characters of the two games; Metal Gear Solid and Killzone.
(Left: Pyscho Mantis, Right: Helghast)
Gas mask reference
My plasticine head was quite hard to sculpt at first, I had to start over numerous amounts of times until i actually got the hang of it. Once i actually understood how the plasticine works and how to design it the way i wanted it to, the head started to look more like what i wanted it to.
I chose to have three expressions, shocked, angry and a normal/neutral expression. Due to the nature of my characters looks, it was quite hard to actually convey different expressions because he is wearing a gask mask, leaving me with only a limited amount of facial features to express his emotion. The main features i used to portray his mood was by his eyes and eyebrows, which showed subtle forms of each expression. After i created all three heads I experimented with lighting to set the mood along with each expression and also did further experimentation in photoshop.
One of the problems i came across was the different colours of plastacine ended up mixing with each other, leaving the lighter parts looking dirty. To overcome this I should have started off with the lighter colours first and then do the darker ones. Besides the problems, I find that my plastacine heads are quite effective with all three being quite consistent and the way i wanted them to look.