I thought the first portrait was fine what did you go and cut it in half and x flip it for? now it's just freaking me out... that first one was far more natural a pose... the hat lying off to one side was nice... symmetry is all well and good but not PERFECT symmetry... it just doesn't exist - there's always some minor discrepancy somewhere...
as far as skills are concerned (pixels wise) I think you need to work your outlines more, try blending them... apply the light source to those too... don't just use a single color line. I can see you've attempted this in places, but you need to be more consistent and braver - push it a bit more and see what you can achieve.
Your anti aliasing shows promise, but again, you need to be more consistent. no aa against the harsh black outlines - but you've nailed it on the smile... just do what you did on the smile elsewhere and your well on the way...
I'm not sure about your choice of pallette... the flesh is a little milky, almost bleached, the red (in the hat) has is not IMO vivid enough, and it's ramp is bit loose... same with the yellow bobble...
Finally... the eyes... need a bit of aliasing too... but most importantly they need some sort of specular hilght... a reflection or two... just off center... this'll give the eyes a bit of 'wetness' and shine... and most of all ...life...
good luck