Fair enough. I don't think it's an ideal form of learning, but it's not against the rules either. 

I pixelled over a reference.

http://i.imgur.com/Cg8IB2f.jpg
I used this as a avatar in forums and I wanted a pixel version...because everything is better pixelled. 

But I didn't use any form of reduction, I just made clusters upon that. 

Midtone, then shades and lights...

Which picture did you use as a reference? I don't think this is low quality work, I just think it's not getting voted up because people are wondering if you pixelled it from scratch or just used color reduction and pixelled on top of that.

Now that I look better there are some things I would like to improve...
I think that I had it so much under my eyes that I didn't notice some stupid errors, even the banding is quite stupid...
I'll work on them.

Thanks! (I don't know how to call you :P )

Good form and it's more than readable but I think the thing that may be throwing the viewers eye off is some of the colours. Especially the lightest blue on his shoulder and lightest grey on his hair. 

You also have a few single pixels here and there and if you zoom in you can also see some banding on the nose There's also one brown colour that doesn't do a lot http://i.imgur.com/kQQ5uW6.png 

Not sure if this is the best critique but it's just a few things that were throwing me off. Good luck though!