I've always loved drawing on various objects! This coffee-lid is from several years ago but I still love it and have it hanging on the bulletin board near my art desk.
I feel like my drawings got a lot more dimensional and interesting once I was able to achieve variable line width. I love loading different colors into the pen and going HAM on paper that totally can't handle it. My sketchbooks crackle when I turn the pages. They buckle and heave and are exhausted from their tribulations.