Thanks! Shading is fun! Though, it gets a little tedious at times. Especially with cross-hatching. I'm able to shade the way I do today because I studied a wide range of shading techniques from different artists (I basically studied the shading in my favorite comic books).
Dark colors work as well! Sometimes I use black or other really dark colors to shade my pictures. I like using crosshatching because it creates a nice texture, and I get to use these tiny tiny tiny tipped pens.