Since you want a critique and you want to get better, I'll rate this 5.
I'll give you a few techniques to run by if you like.
Here is a website for practicing body proportions. http://www.posemaniacs.com/
Use this to practice human anatomy for a bit. After that, if your going to be doing furry stuff, go check out some of Jay Naylor's work.
The thing with lineart and shading is, you need to find something you're comfortable with. I personally go with thicker lines and practice brighter colors, which I would suggest you try. Or, you could challenge yourself a bit more and attempt to redraw other people's drawings to try to mimic their style. It gives you allot of info on the techniques they used.
If you'd like to join my friend, Sam and I on our challenges, just message me, and I'll set you up.
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