O.K. Lets start with the pose firstoff. That's not that bad. He actually does look like he's sitting on a balloon but you could have moved him down a bit more and that would have been perfect.

The form itself is a bit stiff. Yeah I know you might get that alot .. but most of the artists that I know sketch a line of action first (and there's a line of action even with people who are at rest) put the head on top and then sketch downwards from there. That is also how you'd build muscle and such.

Granted I am not the best artist to be giving constructive criticism but I'd figure I would share that with you at least. Also. http://www.furaffinity.net/view/1102042/

That shows you how I draw art as well. If you need any more info or whatever.. I am on yahoo..