Holy crap, souly! I almost #&*% my pants when I saw those shirts, and hoodie. That's amazing man. You should try to open up your own fashion design business, or something. I would totally buy those tops. Would you be willing to sell them at all?

Practicing light, since I definitely need practice in the area. I also want critique, and please try to ignore the badly drawn head and critique my light and shadow, considering this sketch was about 5 minutes lol

I've come to the realization that I suck at painting. I have been really trying here lately to work up some paintings and learn to work with digital painting in Painter X. After failing several times, I now see the problem. It's not so much as I need an art class, but when it comes to painting, I don't know where to begin. I've been fiddling about with sketches, and blank screens for some time, and have no clue as to a good start on painting. I see lots of people say, to paint successfully digitally, you must know how to paint traditionally, with real mediums. Is that true? And I can't afford art mediums and canvases and such. Basically what I want to ask is, if anyone knows of any art instructors over the internet, or someone who is really experienced in painting that I could talk to. I want to be a successful concept artist some day, but that won't come without knowing how to paint, and I simply have no idea where to begin.

Ok, I understand. About my anatomy; as since this is my very first try at every drawing a "correctly proportioned" figure, I am learning the body layout from a frontal view first, to know where key points lie on the figure. I'm following Andrew Loomis' book and by doing so, I'm drawing the male from front, and side views. Once I'm familiar with the skeleton and muscle structures, I'll draw more realistic poses. Thanks for the advice though.

EDIT: As for shading, this is probably my worst area. I need some real practice in shading. Any advice? I don't have a good knowledge of shading at all.

It looks like whatever you're using isn't set to track opacity based on tablet pressure. If you're using painter, try out the other brushes and play around with the settings. When I used it I liked one of the pastel brushes that I modified. But you shouldn't worry about this too much, just try for the opacity, because completely opaque strokes aren't for everyone.

Sorry for not being familiar with this term "opaque strokes." I've been messing around with with Painter's brush settings, but can't find anything I'm really satisfied with. I think part of my problem, as I said before, is I'm not really skilled in the painting area. But for now, I'm not as concerned about the painting issues, because I'm just trying to get anatomy down first.

mm, it's probably a bug in GTK+ on Windows, for some tablet setups on Windows, GTK+ has problems.
OTOH it could be a MyPaint bug that only shows up on Windows -- the main development platform is Linux, naturally.
possibly relevant:

https://gna.org/bugs/?12018
"This is a GTK bug. To fix this someone has to build a new Windows version of MyPaint using a fixed gtk+ version."
^^ the above sounds the most likely to me.. do the described symptoms match?

As far as the Mypaint issue, symptoms are the same, but no fix has been figured out for it yet.