Smooth Shading

A Pencil Drawing technique that is very hard to master and at the same time can bring a photo realistic finish, is the smooth shading technique. This pencil drawing technique consists of shading gradually the drawing with the pencil tilted, to give it a 3D look. This can be done only using the pencil or with the aid of a tool to diffuse the tones. This pencil drawing technique requires patience, and concentration. You have to really have control over the pressure of the pencil, and at the same time choose the right pencil hardness to achieve the desired results. You also have to keep your work clean, because sometimes this type of shading can go wrong, and your work ends up looking bad.

( Source by - http://pencildrawingmadness.blogspot.com/2005/11/pencil-drawing-techniques-smooth.html )