The lines created in pencil drawing depend on the way the pencil is held.There are two basic ways to handle a pencil when creating a pencil drawing.
Writing Position The writing position, or conventional grip, is the most controlled. Hold the pencil the same way you would write, with it resting firmly on your middle finger. This position is best for fine lines and detail. To prevent smudging, put a piece of paper between your hand and the pencil drawing.
Underhand Position Hold the pencil between your thumb and index finger, with the other four fingers resting along the side of the pencil. This position is used for shading effects.