You’re approaching this from the wrong way. Good lights won’t automatically make a picture good. You need to understand what makes up a good image. I did a writeup a while back that can help you get started. Don’t worry, there are plenty of pictures.
To help, I went ahead and pointed out the most obvious things that you can probably work on.
Worth mentioning that the rule of thirds in composition isn’t always necessary, but it’s a great starting point.
Just using some simple cropping, we can already create a much more interesting picture.
Instead of cropping, just zoom in with the camera ingame. You’ll immediately notice that you can focus on a subject of some kind, and this along will make your images much much more interesting.
[editline]19th July 2015[/editline]
Once you have a good angle set up, you’ll find that lighting the scene will become much easier. I talk about basic 3 point lighting in the guide. That should be able to get you going, and since we are in gmod, you can also use more then just 3 lights. Just be careful not to go overboard.
Using gmods fog is an incredibly useful tool for creating depth as well. A very subtle and tinted fog can go a long way to making the image stand out more. A slightly orange/red fog can represent fire or the heat of battle, a green tinted fog can reinforce a jungle/forest theme by making it feel more humid and gross, and even classic white fog is useful in creating an unsettling atmosphere (Silent Hill).
Hopefully this helps you get started.