This was soooooo much fun!  When I first started out I had a bit of trouble becauseI tried using a Sakura Micron pen for the line work.  The paper I used is fabulous for alcohol markers, but it is definitely not good for water-based pens and I kept smearing black all over everything.  After trying a few different things, I eventually found that a Sharpie pen worked best, so that is what I used with the Copic markers.