I believe I've spoken before about how much I love to draw with a simple old bic pen. The bic glides smoothly over the cheap printer paper I often use and leaves a nice clean blue. There's no erasing with a ball point pen so you can't get too careful or fussy. You have to think on your feet when working this way and a little coffee will help to keep you alert and fresh. I often like to start these doodle sessions by drawing the frames on the page first and then challenge myself to put something, anything into each one. This of course leads to a certain amount of repetition but it can also yield happy accidents and pleasant surprises. You have to be willing to take whatever you get when working this way but it's often worth it because there's nothing better than a new idea.
Peace be with you.