This is from THIS POST by Zigraphix over on the Daz forums. Since it’s a reply that’s on the 3rd page of the original post I’m putting it here just so I can easily find the information. All credit to Zigraphix though.
Regarding simple lighting, try this setup. It doesn’t slow down your render much, and will create a world of difference in your images.
1 – create one distant light. Point it from the direction of the strongest single light source in your scene. If your light source isn’t white, change the color of this distant light. Set the intensity of this light to what you think makes sense for the strongest light—if it’s sunlight, put it at about 80%, and angle high, though not straight overhead. If it’s a big glowing screen, 30% might be better, from the side. (If it’s a small glowing screen, use a spotlight instead.) Indoor ceiling lights in a light environment: 50-60%, straight overhead. Ceiling lights in an environment with dark walls: 80-90%. Turn on shadows for this light. Deep Shadow Map will work well enough for most images.
2 – Add UberEnvironment to the scene. Expand the size of the sphere so it’s not in the way of your camera, if needed. Set the intensity to fill in the rest of the lighting in the scene by subtracting the intensity of your distant light from 100, e.g. if your main distant light is at 80%, set UE to 100-80= 20%. You can adjust the color to match the main lighting colors of the rest of the scene, but you don’t need to go crazy with image based lighting—just adding UE will improve the scene tremendously, because lighting in a real scene bounces around and generally doesn’t come from just one direction. Set UE quality to 2 or 3 for a test render, set to 4 for your final render. Turn on Ambient Occlusion—this puts in little shadows where objects are close together. It’s amazing how much this helps the realism of your final render.
3 – For any hair in your scene, use UberHair shader and turn off Ambient Occlusion just for the hair. This will make renders much faster.