Since I draw mostly digitally, I try to avoid the kind of sterile vibe to it by putting high-res photographs of real paper and pencils on a background layer in Photoshop, at least for the rough process. I even add image noise to the background...
Quite recently, an animation student posted a photo of a quick red ballpen drawing I did for her during an animation festival festival in Florence. Today, I used this very photo for a quick process demo.
I often start with certain reference images and then proceed running around on the piece's form and volume on and on and on... lately, I recorded that initial process of mine: