Drawing pumpkins is fun.  Notice the contour lines.  Sometimes beginning artists will make these curved lines incorrectly.   See that the lines on the right side of the pumpkin curve in the shape of the back of the letter D.  The contour lines on the left side of a pumpkin curve in the shape the letter C.  If you turn your pumpkin into a jack-o-lantern, remember that the shell does have thickness.