Well this started out as a simple John Romita (Snr) drawing of the amazing Spider-Man. The original drawing simply showed the character crouching and a shadow. After coloring the image, I decided that Spider-Man would be crawling through a dank tunnel or sewer. I created this background using a combination of layers tweaked using the perspective tools to create the illusion that the tunnel was narrowing behind our hero. After looking at the image for a few days like this, I decided to flip it vertically and add some additional elements - so now Spidey and crawling UP the wall of a down spout, towards the lip of a horizontal section upon which there is a small puddle of water - in my head this signifies that Hydro Man is up there waiting for him.
Btw if anyone has any tips or guides for coloring water please let me know here or over at my site: http://www.localhero.org.uk