ratcharmer: Good sketch; I can only advise you to draw the muscles out a bit more. The better the definition on them, the more believable they get!
SunnyGreens: Sketch is okay (your second one was better); the main problems seems to be that he's stuck between two perspectives, but the lack of definition on the chest might be the culprit there.
bored_ninja777: Try and add the muscles after you have the skeleton, make the lines flow more, and try to get a more organic look. This will increase the quality of the final image tenfold. I'll show you what I mean; I took your image and used it as a base for a quick outline.
Krahhl: The same issue as with your first sketch, and that's a shame. While the proportions have improved a lot, you need to start drawing more loosely; stay away from the straight lines and give him a more natural flow. I tried to show you in a paintover:
Malduk: Excellent sketches. I'd strongly recommend you (and anyone else) to keep practising, even without assignments. As you can see; you only get better!
RavingRabbid: The main issue here, is the lack of shape. Try and build up from a skeleton (in fact; I'd like to see a separate image of that skeleton for the next sketch), and define the muscles a bit more. Try to show where and how they connect, and how they work with the body. Right now, I really just see a big 'O' with limbs stuck on.
wizelsnarf: I have nothing to add to your summary. To try and improve it, perhaps try and use shorter lines; between 3 quick strokes, you often get a better medium than one big one. This gives you more room to 'fix' a line up quickly, too.
Gl1tch: First and foremost;
http://www.splashup.com/ will give you much better possibilities and quality. Since it's free and easily accessible, there's really no excuse to still use MSPaint. If the touchpad is too big a handicap; try going with pencil and paper. Aside from that; you're correct about your self-critiques, and have indeed identified the problem area's. While it seems to worked from the skeleton, you didn't add the muscle groups before really detailing him. That's just a guess, though; but I think especially the midsection makes it show. In the paintover, I tried to show you the difference between lines painted on, and a clear shape to the torso- hopefully it's helpful.
ArtCrusade: The assignment is 30 minutes, not 15. Try and use the extra 15 minutes to go back to your image, flip it horizontally, and fix it up. Pay extra attention to the connection between muscle groups, they seem a bit 'stuck on' as it is, making him look as if he's static; there's no weight or movement to him.
Class is extended for another week due to the unforeseen delay.
