This was pretty much the first time I've done anything human-like, and in the end I was pretty glad how it turned out.
Below is the first draft I put over the white clay.
Next thing I did was I lowered the eyes and remade the nose. Also gave him some proxy teeth/tusks.
Below he does got a bit more mass on the temples and jaw.
Below is a bigger, more shouty mouth.
Below is stronger cheeks and fuller eyebrows.