1. Shade
Firstly, shade the area you are working on to the tone of gray it needs to be. In this example I am working my tiger's ear. I use a 2b graphite pencil to lightly shade, and then go over it with a paper blender to smooth it all out (2b pencils are the best for shading, they blend very well) . Keep layering and blending on the areas that need to be darker. If you need any areas to be EXTRA dark, use a 6b pencil, and blend.
2. Erase
Next, use either a kneaded eraser, or my favorite, a Tombow MONO Zero eraser (it is firmer, and extra small) to create thin, white, highlight lines for the fur.
3.Darken
Lastly, use your 2b pencil once again to go along one side of each eraser line, to add contrast. Only darken one side of each piece of fur (I only went along the bottom of each fur strand).
If the eraser lines are too bright white for the animal you are drawing, you can lightly go over everything with your "dirty" paper blender, to make them gray. Or, if you want extra-white, highlight fur in some areas, go over those strands with a white pen like this Sakura GELLYROLL pen.
And that's all! Have fun drawing your fur! ;-)
~Laree