Hi, great vibe in this image! I'd change these elements in your Mermaid: Hands - get reference images for sure. face - her cheek on the right goes inward too far. Belly button position is too far to the right; belly goes inward, as the shadow under her breastbone indicates. soften all of the edges on the tail, it almost is the most attractive part of the image now. Also the black shadows on the folds (bottom right of image) make no sense, it's transparent material lit straight from above. Simplify the volumes in the hair and make the lines flow, use soft edges and low contrast except for some highlights. Think "ribbons". Keep the color on the tail closer to the green on her hips, and reduce contrast and saturation as it goes into the distance. Add some reflective light to the shadows - under chin, under arms, under tail - in color of where that light reflects from. The teeth are too white. The knife end disappears in the dark illogically. Then send her to me for my aquarium.

