I didn't expect that people will like it that much..Thank you everyone!
and Kimon, I like your drawing, even if you used reference

. Good pencil work and details. And I might try to give you some tips, though I'm not sure if I will be able to write in English what I want to write...my English writing isn't very good. But I will try anyway...here goes nothing-
I think that the 'circle method' will be good if the head looks kinda mangled. First you draw a circle, and then you sketch where the eyes, cheekbones, nose and mouth should be. Then you sketch the rest of the head (basing on the circle all the time), later you put the details etc. But also the Steef head looks kinda different than the human one...For example I use egg as a base rather than a regular circle

I hope that what I wrote here makes some sense...
And here's some more Steefs from me, drawn in school

. I'm learning how to draw their horns and face,rather than being a good student
