I learned a neat trick for working with lighting. When you're trying to get a light set to look right, you render the scene multiple times, each time with only one light on. Then you bring the renders into an image editor, layer them, and set all but the bottom layer to "screen". This simulates what the lights will look like when they're all rendered at once, and you can adjust the intensities by changing the layer opacities until you get the effect you like. For complex scenes, it can be much faster than tweaking a light, rendering to see how it looks, tweaking again, and so on.

Unfortunately, it can be a pain to turn manually off all the lights but one, render, turn that one off and another one on, and so on. Also, Poser 5 seems to lose the light's shadow settings (shadows on or off, raytraced or depth mapped) when you turn it off, and you have to reset them and hope you remember which is which.

What I'd love is a script that notes each light's shadow settings, turns them all off, renders and saves a series of images with only one light turned on with the proper shadow settings, then turns them all back on with the right shadow settings when it's done.