Critiques Help

I've been working on updating my illustration portfolio to present to the Society of Children's Writers and Illustrators conferences.  My goal is to get  10 to 15 great pieces in one to two years.  It's a bit of a challenge I think, and I am frustrated with all the creativity going on in my head.  I get all these ideas, but I can't place them down on paper fast enough.  I really have to think, what angle would be best to present this idea?  What genre do I want my portfolio to present more of?  I really like fantasy novels like Harry Potter, Percy Jackson, and anything King Arthur related.  So I chose to focus on that more.

I really want my artwork to be great in my portfolio, and wanted other peoples opinions on my artwork before I say "It's done!" and just stick it in the ol portfolio. So I joined some online critique forums and facebooks, and started to post my work.  My first one I presented was the Red Riding Hood image below.

I thought, hey it's done, but I feel like something is off a bit on it.  One of the critiques I received was, it didn't show much light and shadow.  I look at it now and it does seem flat.  The wolf's nose is too long.  So I traced the image and recolored it.

I then presented it to the kidlit facebook page to see what their opinions were.  They seemed to enjoy it, and just mentioned a few things to improve it even more. I didn't really feel defeated, but relieved it wasn't a total disaster.  So here's the final piece:  

I feel critiques are a way of improving, and you just have to grin and bare it if you want your craft to improve. :)