Doodles and Finished Pieces

[Chutzpar]

SENOR SLOUCH
I was compelled to scribble all over your drawing >:I



I'll start from the top:
You've drawn the nose a little too far over. THERE ARE MANY WAYS TO APPROACH THIS.
The first one on the left is probably the laziest, but if you're going for a sharper style then it works quite nicely - drawing a line connecting the brow to the nose reinforces the bridge of the nose, which makes it seem more like part of the face, rather than just floating in nowhere.
I added a rough idea of what this would look like in profile: it's a little simple, but it's a perfectly valid stylistic choice. Jamie Hewlett and Kate Beaton both kinda do this!

Second is just making the whole nose wider, so that it's equally spaced between the eyes (it still appears a little to the left, since the head's turned). Here again, it's pretty flat, and also makes the character look rather less elfin and MORE MANLY.

Third is what I think you were probably going for. If it isn't clear, I've pushed the nose back slightly and also drawn in the ridge of the brow between the eyebrows. In case you can't read my awful (but strangely disney-esque) writing: You've shaded the ridge of the brow, but it seems like an afterthought - you've shaded it, but there's nothing in the drawing to suggest it's there.
In profile, the brow would look a little heavier and the bridge would dip in slightly right under the brow, a little more realistically. I was a lazy bastard and didn't draw that. WELP.
Reference here, though:
Linked for pagestretching
This dude's a good reference because his nose is pretty pronounced! See how the brow dips in?
I have only just noticed this in my own drawings. Pushing the nose back and adding that ONE TINY DIAGONAL LINE makes a whole lot of difference in making the face look 3D.

Spoiler (Click to View)

I may or may not have picked this up from copying stills from The Venture Bros

I've prattled on longer than I intended, so I'll try and keep the bottom half brief:
You're drawing the hairline as very square and also a little low, which makes the connection look a little strange at the temple, and also means you'll have less space for the eyebrows, which'll limit how much emotion your characters can show.
On the right I've drawn a slightly exaggerated idea of the average hairline: it bends outwards at the sides of the forhead, and inwards again at the temple. Don't push the ridges too high obviously, or your dude'll just have a widow's peak or a receding hairline, and that's no good.