A pencil drawing in about 2009 when I got started to paint .

That time I didn't know which pencil is good to use , after some times I find out the right way is using some different
various degrees of hardness , to create a nice and soft shading ,
So I suggest you use Staedtler Mars Lumograph Pencils which are great .

The best graphite pencils. Graphite pencils come in various degrees of hardness, from 9H (the hardest) to 9B (the softest)and darkest. . The hardest pencils are used for shading the lightest areas in drawings, while the soft pencils are great for shading the darks and the middle tones.