Your drawing is already very good! For the clothing lines, try adjusting the thickness—use thicker lines for shadowed areas and thinner lines (or even no lines) for the light areas. The same applies to the face. Right now, the eye lines seem a bit thick, which might be contributing to the “unfinished” look. For the hair, try to make it more detailed and pay attention to the direction of the strands, as it currently looks a bit messy. Keep practicing and use reference images for study—understanding and applying what you see will definitely help you improve!