I have a process that I go through when I am adding flash to a scene. The first is that I think of the image in layers. I don’t get too complex with this, but every image has a background and a mid-ground (the subject), and sometimes a foreground. I start with how I want the background, then the subject (mid) and then adjust if there is an opportunity to use a foreground element, but I did not really use that in this image, but the raindrops in front of the couple did add a bit for the foreground.