I think this art needs more color rendering. Colors and lineart are too rough. Try smaller brush for lineart and softbrush for shading.

Next thing is light. Your face and head shadows look like light comes from left top corner. But your shadow on neck says something different. Also, if you've made face shadows, you should add them on body (arms). In comparison to head, fabric has too small contrast range.

And the last advise - try to do more details. Or at least details on the most important part of the art, which will get focus the viewer eye on it.

Good luck in your artist path!