Why do you need a new site for this? DeviantArt does the job well enough, no?

Anyways, when you shade, try making straight uniform lines. You, like I did at some point in the past, have the tendency to round off your lines and quickly back up for the next one (look at the shading on the face and you'll see what I mean).

Next up is the thickness of the eye lines/eyelashes. Most of your eyelashes are drawn pretty thin, don't be afraid to accentuate them a little, even more so in the case of women. Don't go overboard though like you did with the eye in the middle.

Tears unfortunately don't run like that, they pile up on the lower eyelid and then drizzle from either corner of the eye.

Your hands are unrealistic because of their bends. Try thinking of fingers as multiple straight components (cylinders or boxes) with smooth lines connecting them, rather as one flowing segment. Following up on that, try lightly sketching the bones of the hand in the post that you want, and then use your knowledge of anatomy to smooth it out, add wrinkles and bumps of muscle.

The shading on the boot is very good, no problems there.

Eyes (again), when they frown (upper left) they cause wrinkling of the skin, try adding some more lines and accompanying shading to hint at this.

The nose, well that's a stylistic preference so I won't comment on that.
The mouth isn't my cup of tea and whilst it looks all right, it still looks off to me (perhaps due to the lack of wrinkling).
And I'm not going to even try and understand what it is you drew in the upper right corner (some kind of eye with the capillaries clearly visible?)

Sorry if my crit seems harsh and to the point, but I simply want to get you to the next level.
(and if you think it's harsh, then you're really soft, toughen up or you won't survive the internet :P )