Well, somehow the "cartoony-ness" always seems to evade me. Anyway, here's one possibility as to the background.
The fire is a trick I learned in Photoshop. Later we'll compare the pros and cons of Photoshop flames versus painted flames... I could very well be wrong about this decision.
Compare to the blue pencil layout. Some changes have been made, no doubt, but overall it's still the same composition.
Only thing is... what I've got here isn't spooky. It's downright horrifying. It looks like some type of sacrificial ritual is about to be performed in this little copse of trees.
Because the flames look as if they're being blown around in the wind this picture isn't saying "Summer" to me. It's saying: cold and crisp, as in late Fall. One of those clear, freezing nights of the sort you get in the mountains. So as I say, I could very well be making a mistake with the Photoshop flames.
Also, I didn't include the foreground foliage... neither the weeds from the ground level or leaves from above... because that type of cutsi-wootsiness doesn't seem to suit the background. Again, I could be wrong about that. But forground foliage would serve to miniaturize the scene making it safe and cartooney. So maybe that would be a good thing.
We shall see.