I started out in poser 3 and I started out trying to do what you see here, being none of have or ever will see any of that work...I burned it then buried it. I came from byrce 3d, I learned some great lessons in lighting there, course none of that did me any good until Poser 5....In poser 5 I actually created some decent illustrations or scenes.. Still had no idea how to get a handle on lighting and still had big problems trying to take command of the 3d space. Still at the time most every body was doing cheese cake pictures of girls or horses....Not me, I was still beating myself up while trying to show every one that poser could be an illustration tool. I just had a lot of trouble figuring out how to get a handle on both lighting and the 3d space. Ever just sit on a park bench studying four things fore ground, mid ground, back ground and how lighting was needed to show all three....
Course I'm no genius I have only gotten to this point on the shoulders of some really great artists, many of them are here....
Personally, I tend to emphasize lighting aesthetics over realism, which I call "artistic lighting". However, there is a lot of people who only aim for realism. I have spent years learning different aspects of lighting a scene, where I tend to put art and color theory into practice. Things like the effects of light and color contrast to emphasize something, color saturation to add mood, use of perspective (camera lenses) to make things more dramatic, scene placement and balance, camera framing, and light focus.
There is a lot we can do with the basic 3-point lighting that ships with Poser. I use it all the time, though placement and parameters are never the same. Light positions need to change with every character pose, because they each (key, fill and rim) have a different role. My suggestion is to start with the 3-point light, but only 1 at a time. Turn the others off until you are done with the current light, or else it will be hard to see its actual contribution. Dreamlight has a technique where he renders each light separately, and then composes them in Photoshop layers to adjust the individual contributions in postwork. This can save a lot of rendering time if you have a slower computer.
I know there are plenty out there claiming that postwork is heresy, but I am not in that team. I think postwork is not only a good thing - I believe it is essential. All movie production studios have a postwork department filled with talented artists who do nothing but postwork. George Lucas was very proud to show his "before and after postwork" shots of Star Wars (1977), where the differences are dramatic. But it's Ok if some will refuse to postwork 3D renders. To each, their own.