Well ,you've definately improved. I would say to learn the basic shape of a head. The hairline comes too far down, which is a common mistake. Remember there is a head under there. Also the eyes are generally out of proportion to the face. If that's your style, there's nothing wrong with that, but reduce them a bit. Last thing, lips. When it comes to drawing mouths on men, you tend not to detail the lips. Just detail the lower lip, and a small portion of the upper one. Link. It's a pretty good tutorial.