Critique For MY AP2D Projects

I apologize that these are mostly hands however I enjoy drawing hands among many other things withing the range of anatomy. These are three of my projects due at the end of the summer and I was hoping to be critiqued before I turn them in. (FYI I do know that the dark space in the middle of the hand lotus is a bit off setting and if you have any suggestions of what I could do it would be greatly appreciated)
Go to:
http://oukaai.tumblr.com/post/125563107105/this-is-one-of-my-drawings-for-my-ap-class-i-used

I will try to add the others later I have some stuff I need to do right now,sorry.