Apart from the normal method of drawing with a graphite pencil I would like to suggest some other methods of drawing, which will give you a different finish to your work. I occasionally use these methods to create additional interest in the work.
Consider using a stylus to work into the paper before you lay the graphite over the surface. where you have indented the paper you will get a nice clean white line as the graphite does not go into the scored section of the paper. This is a particularly good technique for drawing hair, it allows you to introduce very fine highlights.
The other technique which I enjoy using is taking a sharp blade and scraping the graphite off the end of the pencil.This gives you a fine graphite powder which you can use with a tissue to apply backgrounds over a large area. It is easy to control the amount of graphite you apply so you can effectively work in different layers.
When I am doing my outline drawings, I often use a hard 3h to create the outlines. I also add additional lines into the drawing to create interest. When you draw over these lines, additional texture is easily created which gives the drawing more depth and interest.
Try using small little circles to create a dynamic texture. I often use this technique to reproduce trees, concrete, leather, in fact it is a great technique for producing a lot of different textures.