Tue, Jul 05 2011, 09:01 PM EDT
Because it's kind of depressing to watch you get no responses, I'll cut in and point out that your heads have a very fake look to them, kind of like really detailed Muppet heads. The glass-ball eyes especially help in giving a soulless appearance to them.
My suggestions -
*Less lines on the face. Lines should exist predominantly in places where two shapes overlap. Adding lines where they are not needed creates the appearance of wrinkles, and ages the character considerably.
*Give depth to the eyes. The shading in your sclera (and in general, actually) is given very little contrast. The irises, on the other hand, are much more vibrant and use much stronger contrasts. Try using darker values in your shading.
*The mouth is, for a lack of a better term, wrong. It's too goofy and wide, and the face really draws the eyes to it. The dimples are way too large, too, and look much more like either wrinkles or cartoonish dimples. I'd say tone down the angle of the upturn and shorten it just a little. This is mainly a point in regards to your forward-facing heads; they look better (except for the dimples) from side and angle shots.
*The jaw is too narrow at the bottom, a dog muzzle is squarish from the front not triangular. Also, the muzzle looks to be angled downward in portrait, like at a 45 degree angle. To put it simply, you are using human anatomy rules for the front view, setting the nose at halfway down the head, even though with dog anatomy (and your side view) the nose is much closer to the middle of the face. This part, it's simply best to practice with life references. Try to build a dog head out of shapes to understand its construction and three-dimensional form. Again, this doesn't crop up much from other angles, but it's much more noticeable the closer the head is to facing the viewer.
Anyway, that's pretty much all about the heads. Your bodies are okay, not perfect but certainly passable. The most notable issue is that they're rather stiff at the torso. Most of the pictures suffer from the characters always having their backs straight (and for solo pics, straight up). Drawing from life, gesture drawing especially, can help better understand the flexibility of the torso. Other than that though, they're not bad.