Part of the process of producing a comic page is laying it out. Almost all professional comic book artists use some method of figuring out where all of their dark and light areas go on the page before applying any ink or drawing it up.
After realizing that I had not planned my inking out very well a friend suggested this method of blocking in the dark and light values before going to ink. I have chosen the traditional inking method entailing brush and dip pens, because the blacks are much more potent, permanent, and versatile than using technical pens, ball point pens, and Adobe programs.
My method of blocking in value is to scan in the page in its penciled state, scale it down to the actual page size, print it on gray paper, then use black and white pastel to find the best possible scenario for the values of the page. I have to seriously consider the light source when I do this. Typically when you are working with just lines it is more difficult to consider some of these things ahead of time. Back tracking with this method has helped me think ahead on future pages.