What's been more interesting to me lately than using software to design data visualizations is learning to draw data by hand. It's a time consuming process but incredibly rewarding. The feeling of erasing graphite to reveal clean, crisp lines is something that software cannot recreate.

What do you use to erase pencil? The words "Using an eraser and a light touch" suggest a gum or a vynil eraser. I make a ball with the kneaded eraser and roll it with the palm against the paper.