I have also added the smallest amount of light onto my background plane, the blackness of the dark is pressing in a little too much compared to the environment i created in the thumbnail. Its still fairly dark, but upon seeing the close up shot, you can see the paler grey peeking through between the trees.
Now to building a campfire. I've started with a really basic model and I plan to try a multitude of animation methods to create a more stylised version of a warm fire. It may result in a myriad of planes, it may not. We will have to see, this will require some experimentation!