First of all, if you're having trouble with eyes, then have I got a treat for you: http://sevencamels.blogspot.com/2007...l-on-eyes.html
I just read this last week, and it was REALLY helpful. I actually bought the book in question, but I haven't had a chance to read it yet. Anyway, read through that, and draw along with it. I'd also suggest drawing some eyes REALLY BIG, so you have room to put in all the detail. I know for the longest time I never really learned eyes, because I never drew them big enough to need to.
The blue-haired girl -- nice! The hair looks good, and the whole thing has good form to it. One thing that's bothering me, though, is the lack of different hues. It looks like you're taking one color for the skin, one for the hair, etc., and just raising and lowering the value. Throw some other colors in there -- put some purple in the shadows, some red around the nose and cheeks, etc. Go wild.
The life sketches are good. It's hard to get people when they're not looking away, isn't it? Most of mine are like that, too.
Keep it up with those head planes, that's important stuff. To help with your problem there, the head, when viewed from profile, fits roughtly into a square, with the nose, lips and chin protruding a bit: