I first set up the scene, just something incredibly simple, in this case just a cube which has been loop cut and extruded inwards, a plane which has been subdivided, smoothed and position as a base and the camera. I also deleted the default light.
Next I set the materials on the inner sections of the cube. Be sure to enable to enable indirect lighting in the "world" tab and ensure the shading is set to emit in materials. For this particular project it's best not to have the emitted light too strong so don't overdo it.
At this point you can position the camera and render the image.
It's not looking too bad at this point but that lighting effect can be improved on through the use of Blender's node editor. At the bottom left of the render screen you'll see the option to change the current editor type. Use this to open the node editor and enable the settings shown below. You may want to enable the backdrop option as well.
You should have a "render layer" and a "composite" node on screen by default. If you don't, hit "shift + a" and add them through the input and output menu respectively. Next, all you need to do is press "shift + a" again, go to the filter option and add a glare filter then "shift + a" again, go to output and add a viewer. Then, by clicking and dragging the yellow points on each node, connect them all as shown below. You may need to lower the "threshold" setting in the glare node to see the effect properly.
From here you can play around with the various settings on the glare node, changing the type of glare, the intensity or size and so on. Then you just need to hit the little render button on the Render Layer node to render the image with post processing. You can see a comparison of the results below and just how much a simple glow effect can enhance the feel of a scene you're working on.
