I seldom use Poser to render, mainly because DS is what I learned with and am comfortable with and my almost non-existent free time doesn't allow me to learn too many new things well, so I stick with what I know. For those who don't want to use overlays to modify the actual texture maps, there is this post in the DAZ forums explaining how to use them in Poser 7. I have not tried it though, and don't know how it works, nor if it has limitations in versions other than the one the poster used.

using overlays in Poser