Here are a couple of panels I recently finished (I'm not showing many full pages at this point to avoid spoilers).   I chose these two, from different pages in the story because they share a similar shape and both feature silhouettes, but are otherwise so different I thought I'd post them to contrast and compare.

The panel on the left is unique to the book, as it's the only panel not set in "reality" (it's a memory), and its also the only panel that crosses over with a scene directly from the movie (Doe hitting Mills in the head in the alley).  So I decided to draw it in a more abstract way to make it stand out from the gritty textured look of the rest of the issue.  The result reminds me a bit of the work of Saul Bass, the artist who designed many a Hitchcock movie poster.

The panel on the right represents a turning point in the story for John Doe, where he decides to sacrifice himself to do God's work.  The staircase is him figuratively descending into Hell, as a result of his own sin (envy).  But Hell is a light at the end of the tunnel for him, because it's showing the path to complete his mission. 

David Mack actually wrote this panel as Doe walking down an alley, but I was inspired by the last scene in the movie ANGEL HEART in which Mickey Rourke's character descends into Hell on a freight elevator inside (what I think) is the building featured on the cover of Led Zeppelin's Physical Graffiti.   At least it looks like the same building to me, and the themes kind of match up.  Elevators don't really work for this sort of thing in comics, because without "speed lines" or some other ploy, it's difficult to tell if they're ascending or descending.  So I chose the staircase.