When you're keeping a monthly comic book on schedule, there really isn't an opportunity to "redo" pages. On the other hand, if you have serious doubts there is a window of opportunity to change your mind. Sometimes the window was a little wider than it was at other times:
FLIGHT -- Issue 151 page 11 - The scale -- or, rather, Scale -- was too small for where I had left the cliffhanger at the end of MELMOTH. We needed a big two-page spread of Cirin culling the library and then have you turn over the page and see FRAGMENTARY images of Cerebus attempting to flee, sword first. There. THAT'S Scale. You can see the order the process went in: light sketch layouts, then the border tape, then starting to tight pencil. I did get as far as tight pencilling the bottom right panel before I went, "No, I don't like it. WHY don't I like it?" Answer: no Scale.