All my textures are made 100% in photoshop. I use photo sources where applicable. The only thing taken from a photo on Duke here is the skin, flower petal, underside of his boot, and some of the seams on his pants and boots. I'll more than likely use a photo for the belt buckle and spurs, too.
Pretty much everything else is just using brushes; layer options for beveling, drop shadows, etc; and some filter effects... not too many.

Here's what I got so far. I know I'm using more textures than a real game would probably allow. ;P
EDIT: Removed old image.
Sorry for the size.