I really like the messy free hand style you have going on here. It adds a warmth (for lack of a better word) to the drawings. It gives them a raw look that works well with the ballpoint pen and the messy/chaotic crosshatching.
The only problem with free hand is that proportions and anatomical structure become a lot harder to keep correct/consistent. Try using the pen as lightly as possible (almost putting no pressure on the actual paper) to map out the proportions.
I like the shading you have going on here, but if you want to get a bit more values out of your pen then try tightening up the lines. The faster you put down a line, the straighter it will be (also if you keep the lines short, the longer the line then the harder it will be to keep straight). Try doing some cross hatching exercises. no drawing, just crosshatching.
As for shading hair in pen, you might want to check out this video.
Pay attention to how the artist blocks in the hair, then shades it from the darker spots first, working out to the lighter parts. You don't have to draw every single strand of hair, you just need to show the shading of it.
The first piece is very well done. The style reminds me a bit of the Matryoshka doll (russian dolls) when it comes to the big eyes and small nose & lips. I think it works and it definitely has it's own style. The choice of colors works real well, but the green background could have been a bit lighter. The dark green and the brown hair blend a bit (very earth-ie tones). I also like the texture on the octopus.
The bottom piece is painted well but the proportions are off on the figure (the head looks a bit too big & the right hip looks off, the leg just blends into where the hip should be. It could use a bit more definition). I would practice drawing some figures and look at some anatomy books/images if you are going to go for a more natural look.
The best advice for working with 30 second poses is this: Capture the movement. Don't focus on any details, don't shade anything, and don't rush yourself. The drawings can be messy and that's perfectly fine. The drawings don't need to be perfect or anything close to it. Just try to capture the movement and with time you'll start to notice a big difference.
I personally have a sketch book just full of 30sec and 1 min drawings. Whenever I flip through it I immediately notice a steady improvement. A bit of practice everyday will help out big time in the long run.
The sketches in your link are good. You got the right idea.
Great work on your first color study. The shadows and highlights are great and the movement of the piece works real well. What I'm about to say is really just knit-picking.
I feel like the shadows on the white pants could be exaggerated a bit more. The lack of definition on the left leg and left arm seem to make them blend together (up near the other guy's head). The movement is enough for the viewer to understand what is happening but I think if the overall coloring was a bit sharper then it wouldn't have this problem.
Did you do this in Photoshop? If so then you might want to take a look at this program http://www.madewithmischief.com/index.html Its called Mischief. It's designed for digital sketching and painting. It also has an infinite zoom, which allows HD imaging at any scale. There is a free trial download. You might like it more then photoshop.
