Draw an oval for the skull shape
Add a horizontal guideline through the middle
Add a vertical guideline down the center
Sketch the cheekbone area by widening slightly below the midpoint
Draw the eye sockets as two large almond shapes on the horizontal guideline
Shade in the eye sockets lightly to define depth
Add the nose opening as an inverted triangle or rounded trapezoid beneath the midpoint
Draw the nostril openings within the nose shape
Outline the cheek contours leading down from the eye sockets
Draw the upper teeth line as a shallow curve under the nose
Add the upper teeth as evenly spaced rectangles or rounded shapes
Draw the lower jaw shape with a curved line from the cheek area to the chin
Add the lower teeth as smaller, slightly irregular shapes beneath the upper teeth line
Sketch the chin as a rounded point or slight dip at the bottom center
Add the jaw structure by connecting the cheek area to the chin with angled lines
Draw the teeth spacing and slight separation between teeth
Add the cheekbone/temple shadows around the sides of the skull
Refine the brow ridge above the eye sockets with a subtle curve
Add the skull cracks or texture lines if desired
Erase unused guidelines
Darken key outlines and deepen shadows around the eye sockets and under the nose
Add final shading under the jaw and around the sides for form