Help me out, please?

[CFNstudios]

I've seen many people on Newgrounds showcase their awesome artwork, and it makes me feel jealous. I want to be able to get in on this, too, but I think I need to learn from you, and my own mistakes. I've always been able to draw well, but I want your advice and opinions.
Here, I will draw a random picture, and you guys tell me what you think, give suggestiond and whatnot. And please, give constructive criticism.

I used this drawing as an example on somebody else's thread. My drawing is on the right.

[Kinsei]

the jaw needs to be more defined and proportionate to the rest of the head

[Weenog]

both an artists curse and blessing is never being content with the things you draw.. it will help you strive to be alot better, but will also prevent you from truly appreciating your own art to the fullest.

[MPoulter]

The jaw needs to be longer and brought a little farther foward possibly as well. The ear is completely out of perspective-you're using a side view while the ear appears to be in a frontal view. It's not bad though. I know what you mean about jealousy too. It sucks that there are so many awesome artists out there. My advice would be to look at how certain artists create certain effects. Don't steal anything by any means, but make a conscious effort to understand why something you like is good.

[Ansel]

the main issues i see with your drawing are that his forehead is too low and his head is set too far forward. Whenever you're drawing a human head, remind yourself that the skull rests on the neck -- it's not some kind of cantilever thing, all the weight is directly on the spinal column and the throat. Secondly, the skull is, while not completely round, a fairly elliptical shape -- some people (aka the deformed) might resemble your image, but an average person has a domed, bulbous skull and a fairly high forehead. Look up facial anatomy and bone structure, and keep in mind that all the muscles and fat connect to the bones of the face, rather than just floating.