Finally getting around to the long-promised critique. Sorry this took me so long, I have been very preoccupied!
First off, I'd like to say you did an excellent job with the colored pencils. Usually, when people use colored pencils, they fill an entire area one shade. I think you have excellent grasp of gradation in color. The shading is also very nice, especially down by the foot on the right. I think you've found your medium. But perhaps experiment with different kinds of drawing utensils? Try your hand at pastels or other things and see how they work.
I noticed the outlines are a bit choppy. I'd work on smoothing out your line art, even just a little edge around it to smooth the lines. I think it would look much cleaner and more professional.
I like that you gave it a facial expression and position instead of leaving it as just a boring portrait, but it would be much more interesting to see it interacting with someone or something, or giving the picture a background.
Overall, nice grasp of the colored pencils and shading, but be sure to add an interesting environment as well.
Sorry I haven't gotten to this yet, and it might be a week or two before I do. I've been busy and I may have some difficulty accessing the internet. I will eventually, though! Sorry for any inconvenience!