Everybody stand clear! I WILL divulge!!... Seriously, I use primarily Faber-Castell pencils, 2H, H, HB mostly. First sketch on white drawing paper or card stock, then trace over with parchment tracing paper, around 8 and a half by 11 inches paper size. I scan to computer and tweak color to sepia, and clean it up a bit. Typical working method.
I do a preliminary sketch, put tracing paper over it and do a "tight" sketch, I scan the tight sketch, tweak it a bit, and print it to parchment paper card stock, then I darken, shade it, and define lines better. It's actually on that paper!