All of my doodles are drawn by hand. I use pens, markers, pencils; just the basic stuff. I let my hand take over, and when I finish a doodle I pass it on to my design assistant; my Right Hand Nat.
She then scans it and turns it into a printable image that is ready to color.
In this age of computers doing and running everything, I thought you'd like to know the most important step in creating my Abstract Doodles does not involve machines. -NOR China, just my hands :D