Well Sam, actually I did not 'add' the streetlamp light.
I duplicated the backgroundlayer and applied a photofilter (warming filter (85) at 100 %)(or color at will).
Then I added a layer mask and brushed away (depending on the brushhardness) until the remaining lighting.
For the rimlighting on exposed objects and the fence I did the same. On some parts I used the dodge tool to accentuate the effect and fade the orange color. It's a bit more work (ctrl+z) but the result seemed good.
I did the lightbulb with a zero hardness brush.(Pressed until the result was good)
For the rimlights on the roof (white moonlight) I used the dodge tool.
I forgot to say that on the first duplicated backgroundlayer I did an adjustmentlayer 'moonlight' and correct it to darken the blue color. (I am using CS6)
Well Sam, in the first case I used a layer mask on the 'blue' background and brushed away the gate with under it the 'orange' background. I highlighted some parts with the dodge tool.
On the shutters I used the dodge tool. (after masking with the polygon masktool)
The rest will follow tomorrow, I'm leaving for bowling practice.
See you tomorrow.
@hershy314: thank you for the comment. By the way, this is not a technique I invented but borrowed from a tut I saw about a month ago or so. Of course mine was my own interpretation.
It took me half an hour to find it back but it comes from here: https://www.youtube.com/watch?v=HXZOKqDbgpY
@chrisdesign: also thanks for the comment and yes, the black cable is disturbing. At first I was planning to add rimlight on top of the cable caused by moonlight . But I think that the focus is the alley itself and too much detail arround could take away the focus.
I'll remove the cable and post an update.
Here is the update