This is a quote from an interview with him that really made a lot of sense to me. You can find the whole interview here http://blog.hulu.com/2010/06/21/about-the-artist-pascal-campion/.
"How did I get so fast? Practice and choices. I draw every day of the week, and I try to rest on the weekends. Drawing every day at the same time has helped me to become more efficient. But something else that is as important is the choices you make as an artist. I chose a long time ago that I wanted a style that was fast. I did gouache paintings when I was younger, and would spend a whole week on just one painting. It would look realistic and pretty good, but I would get bored of it by the end of the second day, and the rest of the time, it was a grind to get back to it. After the painting would be done, I felt drained of energy and disgusted with art. I realized that,although I admired art that was extremely rendered, I was not enjoying doing it. Thatâ€™s when I started working on developing a way of drawing and finishing my drawings that would be fast. I wanted to be able to carry a message through the image, and still have fun doing it. I worked on simplifying my shapes, figuring out what was important to say with the image, what was not, what was pretty but unnecessary, and what I absolutely needed to spend more time on. I still feel like Iâ€™m not there yet, but at least I still love doing my images and I feel like I keep growing as an artist! "- Pascal Campion