Tried Red-Lining

1)Action Lines are important. They make drawing simple to dynamic poses much easier. 
2)Try to keep them more balanced. When a pose starts to lean it either implies movement or looks odd.
3)The hand position seems off. I think its because the ribbon and the neck piece show the wind blowing -> way when the hand looks like its brushing hair blowing <- way.
4) The shoulders are to straight. When arms are on different levels the shoulder are usually as well. Plus it adds to the pose.
5) The arm is very close to the body. When limbs are close to the body they make the pose harder to see.
6) As stated before the wind for the clothes and the hair seem to going in different directions.
7) The torso shouldn't get too skinny. Especially in the ribcage area. The ribcage is a solid round object that doesn't squash or stretch. This also applies to the hips.
8)Seeing how the ribcage and hips are rigid parts of the body the twists happen in-between them in the soft flexible stomach area. 
9) Make sure when the person is sitting they are level or have the butt area flatter to show the weight of sitting.

Hope this helps!

Original work done by SPKMatsuda23