Sunken Sturgen in Colour

Crayon on paper. This is a final drawing for class, and I hope to work on the painting over the summer. If you have any ideas or critques I'd be happy to get the feedback. I know that the hand is weak, and the contrast is not as strong as it could be. But when working with crayon, it is sometimes very hard to get fine, tiny details to read well. If you have any tips with crayons or pastels as a meduim I'm all eye balls.