This is good work

It definately needs a transparent background and like already stated, the black for the mouth and eyes is a little too dark.

Overall though it's a pretty good skull

Title changed

Nice shape.
I agree on not being a tutorial, seeing as there is no step by step information, but it can easily be changed into that.
My two crits on the piece: i) You've got a grey in there which is almost invisible on the white, ii) the black is far too dark, I'd suggest a dark grey.

Overall, some very nice work.

not really a tutorial, more of a "progress", but looks good anyway.

id say it looks quite realistic, though maybe it would have been nice to put another bone next to it, and give the bone a yellow tint next time, it looks a bit too clean now...