Rudy Giuliani sketch in ball pen. I did a marathon of quick sketches when I realized I cannot have access on my charcoal pencils and paper- I left it in another place. I wanted to prove to myself that nothing can stop me from doing art. I'm not working that day so I thought that I might as well be productive. And I did.
Artist Bobby Chiu once said that," artists don't have to look for inspirations before they could do art. They must train themselves to get into it at anytime, everyday. Once you get hired for some artwork or commission, you have to start right to it and beat the deadline no matter what!"
Pen and paper- that's all I need.