Sketch

For those aspiring design renderers, notice 3 key ingredients:

1) He moves the page! Mike is constantly turning the page so that his fingers and wrist can draw the lines comfortably. Think of this as "drawing with 2 hands."

2) He keeps a supply of sharp pencils! This is critical: you can't get that line quality unless you start off with a nice point and work down from there.

3) He uses the tip as well as the side of the pencil. Duh, but you'd be surprised how many designers forget to change the grip of their pencil while sketching.

via: core77