I have never done this before, but here is a glance how I made this photo.
I shot the background image on one of the most gorgeous sunsets I've witnessed. The rain made the light glow in this scenery perfectly.
The first thing was to clean up the scenery from all the distracting details.
I decided to go for a b&w layer and on top of that create these moody green/blue hues with curves adjustment layer. Then I went and added the tree from one of my pictures I took.
Final editing were to add shadows and birds to make it look even more atmospheric.
Hope you like it!