Well I started off tweaking curves, levels and vibrancy and wasn't really happy soooooo.... I decided what was needed was a time of day change and then probably needed the moon too to brighten up

. I did leave as colour but turned my black and white back layer back on and it looked much better so that's what I went with.
Now I realise I am probably nearer one side of the rules but having a quick check of some historical stuff I feel it's ok- no fictional or out of place elements have been added like flying badgers and I thought it might be good to write out the steps as it's something more unusual for this thread.
Edit11 by
Dr_Ozone, on Flickr
Okay steps (CS5)

(more due to my haphazard workflow)
1.Duplicate background in case of accidents

2. Create new layer (best called stars but I'm lazy and don't bother) with mode set to screen then tick fill screen with neutral colour (black). You could also create a new layer with mode normal and then make foreground colour black then go to edit and fill
3. Go to filter> Add noise- here I had it to about 80% but have used 100-110 in the past, guassian and monochromatic checked.
4. Next go to filter and blur- I selected 0.4 pixels
5. Then choose filter> new adjustment layer> levels. You want to check the 'use previous layer to create clipping mask' so that it's only affecting this layer
6. Muck about with the sliders moving black to the right and basically moe around until you like what you see
7. Now move the stars layer and the adjustment layer below your background copy
8. Take the eraser (i like a soft edge brush) and brush over the sky and the stars will come through. I brushed out some of the fence as this bit is quite footery and I'm really slow

9. Next I created an adjustment layer linked to my background copy for vibrancy and tweaked that a bit which brought out some texture in the fence and rocks
10. Next created a black and white adjustment layer
11. Create new layer and add 1 moon (cos we live on earth and only have 1) cut out from pic with quick selection tool then use move tool and then use edit> free transform to sort to size and then with a very low opacity (about 10%) brush brushed over that with a large brush and then used a smaller brush with about 20% and then a smaller brush again with about 50%- so every decreasing around the moon.
12. Did a slight crop
Probably easier more efficient ways to do it I'm sure
