I've had a few queries about the cover sketch process, most of which I can't answer because it varies from editor to editor. One point I can address is that it isn't always as smooth as some of my earlier posting might suggest.
The initial sketch for this Marvelman cover was a little too woolly and vague so Big Ben wasn't recognised during the approval process. Clearly visible in the final pencils I discovered there were legal issues preventing Big Ben appearing so he had to be removed. Rather than erasing the figure and risking damaging the page surface I drew the correction on a separate patch which I inserted after Mark had inked both parts.
Due to e-mail gremlins this Star Wars cover became a rush job and my initial very rough sketch was sent through the approval process. The image was approved with the proviso that the Stormtrooper Chewbacca is tossing in the air was removed to avoid any risk that it might appear the Wookie had knocked his attackers head off. Without any time to propose an alternate solution I did as asked but I don't like the finished image, The image is busy enough not to have lost any compositional balance but Chewbacca's raised arm seems pointless and ill considered.
The published version of this 'redacted' cover from the Marvel 75th Anniversary Celebration was far more redacted than I had expected. Certainly one of the strangest jobs I've done-- ever.