If I can give any hints from what I learned in creating my "Rawn Zombie" texture at DAZ, I would say... In creating any good texture, it is important that you start with a good base, and then build on there. For any human (or once human) characters, you will still need to start from that primarily human look. Meaning you will need a basic skin tone to build on top of. Then you can adjust the saturation to grey out the colours to achienve whatever level of "death look" you are looking for. Then you can work on building up colours again to give the overall appearance you are looking for. Once you have this, then you can build on whatever extras appeal to you in the way of wounds, wrinkles, blotches and other things. You have a nice start here...keep us posted as to how it goes.