I see you have the basics of lighting down but you should really learn how to draw line art better and try to make your sketch look more natural befor inking it in. This is just super stiff. You should look up gesture drawings and practice that to help your art "flow" more. You also shouldn't be afraid of using more colors when you shade. You should check out my art. Altho it might not be anatomically correct, it's still aesthetically appealing. ^_^ good luck with all your work