I used google image search for references. (skull and suit) I photoshopped the skull to replace the mans head, to give me a good reference. And then I sketched what I saw, and then painted it, with some changes. :D I use Wacom Bamboo Pen and Touch. It's and old model, the drivers are a little but buggy, but it is my first one so I have to like cuz' I don't have another. :D For program, I use mainly photoshop, sometimes MangaStudio for linework. I hope it helps, if you have more questions, feel free to ask. :)