Here's some tips I made, it is kinda rushed since I'm at work. (You can pass them up of course, I am no pro).
First one: When working values with colours, always try to change the hue when going through lights and shadows (i.e.: Your rock up there, the texture you've done is beatifull, but the colours are a bit flat, when painting it, you could add all the colours, some green reflected from the grass, brown/red from the earth, yellow/blue from the atmosphere and so on). I did some prints and pasted the colours used, yours falls almost on the same range of hue, that happens when you only add white on lights and black on shadows. A good practice for this is a monochromatic piece, try to make a still life painting with all the colours, but the result will have to be a "blue painting". Confusing huh? It works, here's an example : http://3.bp.blogspot.com/_z_-1YfOJXt...0/DSCF7069.JPG . It is mostly a blue painting right? But it has yellows, greens, even a bit of red in it.
r_zanchetin: Man, thanks a lot for the advice, I'm trying to incorporate what you said about different colors in everything I do now, and definitely seeing a huge difference. I'm going to do a touch up round of all the illustrations I'm making for my portfolio after they're done, to implement all the feedback I get. Again, thank you so much!
Frostelle: Thanks, will remember to focus more on anatomy in my studies!
Now for a little update, a couple of speedpaints and a study from the last few days. I still havn't gotten to a sketch that I'm happy with for my next portfolio illustration. I don't think it's a bad thing though, because I want it to be something I really like and have confidence in right from the sketch. So much to remember, so much to learn!
Have been living with my girlfriend for a week, not being very productive.. Just started a new piece, although I'm very unsure if it'll be a portfolio piece yet. Which means most likely it won't. But yea.. Here what I got so far.