skull sketch

not bad, but practice your shading techniques. the shading isnt bad. you have some depth there,but with shading you also want to create contour. like in the eyes and nose. instead of going straight across, try rounding it out a little to give the perception of the depth, and an eye socket. try to pay close attention to size and proportion also. the eye on the left needs to be slightly bigger, and have the same downward flow from the nose as the other eye……overall good job.