Nice posing. I generally don't like photos that look down at a model, I think it causes more problems that you have to deal with, like perspective and vertical lines that are no longer vertical. Get on their level. And with female models, it does appear like you're trying to look down their shirt, IMO.
Pretty girl- I like her smile and also the serious shots. Great job focusing on her eyes, although I think you can use just a tad more depth of field on #9. What kind of lens and aperture did you use on these?
I like how her hair thingy and her shoes match in #8. That's a great, relaxed pose. I think that's the most interesting picture of the group, and that's the winner for me.
Great set.