The Chalk Brush

This is a simple question that will probably have an obvious and simple answer. But here it goes: How does Mr. Lafferty make his shading so smooth with that chalk brush? I downloaded his brushes from his DeviantArt, but no matter what I do it turns out extremely dark and extremely grainy. Is he using a specific eraser that he goes back in with after laying down the shading on his initial line art? Or are the brush settings different from when you download the brush, and they require some tweaking? Forgive me for the silly question, but I am a noob when it comes to photoshop.