Part 2:
The idea here was to make the scene look dirty, as if Venice is in a state of deterioration. I started adding some textures, such as junk, rust, brickwork and corrugated steel, by simply cutting and pasting from other photos. I then played with the levels sliders and various overlay/transparency modes until it looks like a natural part of the image.
I also added more pieces to the background, like some barbed wire on the rooftop and some pipes on one of the walls, generally repeating the same processes detailed in part 1.
In a new layer, I began using some custom brushes (download here and place in your Photoshop/presets/brushes folder) to add a bit of dirt and grime to the scene.
I decided to flatten the image (make sure you’ve saved the PSD file with the layers preserved before doing this). I duplicated the background later and applied a moderate gaussian blur filter. By setting this layer to hard light it softened the image and added some extra shadows. I decided to erase through parts of this layer with the eraser tool and a soft brush in order to create some highlights. I then lowered the transparency again to soften the shadows.
I created a new layer and applied a basic black to white gradient. My aim was to get it to coincide with the lightsource (the sun in the sky). Because the church is in the way of the sun, it will cast its own shadows so I flipped the gradient around so the dark area falls on the right, in front of the church. I set this to multiply (which retains the shadows, but removes the white) and reduced the transparency.
Part 3:
Time to apply some colour. I added a new layer and filled it with orange, before applying the clouds filter. This underpainting layer adds warm tones to the image. I strengthened the contrast using the brightness and contrast sliders, set it to color and lowered the layer transparency. I rubbed through areas of this layer with the eraser and a soft brush.
On a new layer, I started airbrushing some blue into the shadows to add a cooling tone. I set this layer on overlay mode and adjusted the transparency so that it’s not too pronounced.