This is my first critique, and I must warn you that I'm not very good with words so excuse me while I'm being blunt and please don't take it offensive if it hurt you.
Let's start with the positive first. I love the way you drew the hair. I like softness of it, you gave it just enough volume to make it look a bit "puffy" and flowy and soft, and that's very pleasing to look at. I also like the amount of detail you put into the hair. Also, the yellow outline is a very nice touch to the whole thing -- it's simple, yes, but it instantly makes the whole thing look complete and more interesting.
However, you need to work on your anatomy a lot. Especially with the neck, arms and hands. - The neck is drawn *far* too back, and that makes the head look displaced(although the only thing wrong is the neck). Move the neck to the left a bit, the line you drew here should be directly beneath the mouth. - The upper left arm is much too long. If you look at your own body, you will notice that your upper arm is about the same length as your head, you can apply that to anime drawing as well. - I can't really describe how to draw hands to you, you'll have to look at other drawings by good artists and look at real-life examples. - Shading is another thing, I can't explain it to you, but here I will tell you one thing: don't ever use black like you did with the dress. Use darker shades of grey like you did with the hair. - I do like the way you shaded the hair, except that I think you did them too quickly, so they look a bit messy.
I think that's about it from me. This is my first critique, sorry if it's bad, and I hope it helped you