Personal work I've started with the adhered skulls about 3 years ago, with some reference photos (most of them taken by myself) but lost inspiration and patience after a while. About two weeks ago I decided to finish it and found an old pencil drawing of mine that seemed to be the perfect background for it (It was a drawing of a rotten sperm whale's heart). I've coloured and overpainted it digitally and added some things to cover the wall behind the skulls. Most work done in Painter with a Wacom tablet and Photoshop.
Edit: I've uploaded the image with my homepage in it, sorry for that, but I have noticed that someone has uploaded one of my paintings on facebook and pretended that he has painted it. So, I'm afraid, I'll have to do this with all my paintings in future...