Recently, one of my talented friends at Dreamworks posted some digital art that strikingly looked as if done with a traditional graphite pencil. She provided a link to the creator of the amazing brush for Photoshop. I highly recommend downloading it. It's free! Anymore I just sketch things out on the computer as I can move quickly to the digital Illustrator or Photoshop work (plus having a Cintiq makes digital sketching easier). This brush helps make that experience more natural and realistic.
Here is the link: http://www.macalabs.com/blog/2014/11/18 ... a-ps-brush
Download and enjoy!