Proceed to add tree behind the castle. Place the tree image in the main document. Scale the size as needed. Position the tree layer under the castle layer. Set this layer to multiply blending at about 50% opacity. Mask the edges of the image where needed.
With the same ways place more other trees behind the rock on the left and right sides.
Well here is the complete composition of the scene we have created so far. Next following step, we will do color adjustments to every object in the scene. We will use the color tone and mode of the background (cloud image) as reference of the color adjustment.
Let’ set the color adjustment for the rock layers within the rock folder. Open the rock folder and select the first rock layer to be active on it. Go to layer > adjustment layer > hue/saturation. Make sure to give this hue/saturation layer a clipping mask.
Set the values of this layer as indicated in the screenshot.
Give this layer another new adjustment layer with a clipping mask. This time choose color balance and set the values as the one below.
Then we need to add some highlight to the upper edges of the rock. To do this, create a new layer (Shift+Ctrl+N) with a clipping mask. Take a very soft round brush set to about 30 px size at 20% opacity. With color of #c3dbe8, paint the edges of the rock to give them some highlight.
Do color adjustment layers to the second rock. Firstly give it hue/saturation layer with the same values as the one used for the first one. Then give the second rock brightness/contrast adjustment layer with values indicated below.
Finally, give the second rock color balance adjustment layer with the same values used for the first rock. Here is the result:
Proceed to give color adjustment layers to the left rock layer. Give these new adjustment layers clipping masks. Make sure to position the layers above the texture layers within the left rock folder. Here are the adjustment layers to be given:
Make sure to hide the effect of the brightness/contrast layer by masking on some areas as pointed by red arrows. This will bring back the original brightness of the image. The areas are parts where the moon light is supposed to be more casted. So we should reveal them.
Finally, create a new layer (Shift+Ctrl+N) with a clipping mask. On this layer, paint soft dark blue color on lower areas around the left rock.
With the same techniques, set color adjustment to the right rock.
Mask the brightness/contrast layer on areas pointed by red arrows.
Finally give color balance layer with the same values used in the left rock. Here is the result:
Do the same ways to set color adjustments to the caves or tunnels. After that, create a new layer with a clipping mask. On this layer, paint some white lines around the tunnel and some dark blue color inside it.
In next following steps we still set color adjustments to the other objects in the scene. What we do here is just repeating techniques we did in previous steps. We just apply three adjustment layers to the other objects like we have done to the previous objects. Play around at hue/saturation, brightness/contrast and color balance to find desired result of each object. Here is what I did for the rock in front of the left rock.
Do the same ways to the waterfalls.
And finally here is the result after setting color adjustments to the bridge and castle. Just play around at the three adjustment layers mentioned before. Make sure to give a clipping mask for each.
Now we will set overall color and mode for the entire scene. To do this purpose, make sure the adjustment layers we are going to create are placed in topmost position in the document. Go to layer > adjustment layer > selective colors. Set the values as given in screenshot. Set this layer to normal at about 15-20% opacity.
Give another adjustment layer: gradient map. Set this layer to normal at 100% opacity.
Here is the result so far.
As we can see, the gradient map layer has made the scene a bit darker. We should hide the effect of this layer a bit to certain areas around the moon and sky, top of the left rock, waterfall and right rock, and anywhere else where needed.
Here is the result after doing masking on the gradient map.
Give the scene another adjustment layer: color balance set in normal blending at 100% opacity.
More adjustment layer: brightness/contrast
Mask the brightness/contrast layer to hide its effect to areas indicated by red color.
Duplicate the brightness/contrast layer. Set the original layer to normal at 100% opacity and the duplicate set to normal blending at about 50% opacity
The last overall adjustment layer: selective colors. Set this layer to normal at about 70% opacity. Select all the adjustment layers and group them in a folder. I named this folder general adjustments.
Proceed to add some light to the tunnel. Open the nebula image in the document. Scale the size and place it above the left tunnel. Set the blending of this layer to screen at about 85% opacity. With free transform tool, warp the image to alter its shape. Mask some areas where needed.
Here is the result after giving light to the other tunnel.
Now we will add more illumination inside the two tunnels. To do this, create a new layer above the general adjustments folder. Fill (Shift+F5) this new layer with black and set its blending mode to color dodge at 100% opacity. Take a very soft brush set to 20-30% px size at 3-5% opacity. With white color, stroke the brush on areas where needed to illuminate them. Here is the look of the layer in normal blending for your inspiration.
The result should be like this:
To give a nuance of life in the scene, I decided to add a figure in it. I used this model as the figure.
Here is the figure will look like after I did some retouching on it
Add the figure to the main scene. Place this figure layer on the bridge. Scale its size to proper one.
Finally, we will add some light on the hand of the figure. Create a new layer above the general adjustments folder created in previous step 20. Set this layer to hard light blending at 100% opacity. Take soft round brush set to about 10 px size at 100% opacity. On this new layer, click the brush with color of #fe7303 on the right hand of the figure, this will give an orange spot on it. Now set the brush to smaller size at about 8-9 px. With white color, click the brush once again on the orange spot. This will give nice brightness on it.
Finally, we will do last adjustments to some objects in the scene. Create another new layer above all the other layers and folders. Set this layer to hard light blending at 100% opacity. On this new layer we will do final touch to the screen. Take a very soft round brush set to about 15-20% opacity. On this layer, paint some soft dark blue color on certain areas around the upper, lower, left and right edges of the scene. Then, take white color to paint some more highlight on the upper edges of the rocks and waterfall. Use small soft round brush to do this. I also painted some contour inside the right tunnel. For our inspiration here the layer I created look:
And here is the result.
Proceed to do some adjustments on the bridge. Go select the bridge folder. Create a new layer with a clipping mask within the folder. On this folder we will create some highlight on the upper part and some shading on the lower part of it. Take soft round brush and paint the highlight on the upper part of the bridge with color of #eaf5fe. Then paint shading on the lower part with dark blue color.
Now open the castle folder. We will do the same ways to add highlight and shading on the castle. On the new layer, paint soft color of #eaf5fe on edges of the castle where the moon light is much casted. Then, with dark blue color, paint some shading on the wall of the castle where the moon light is not much exposed.
Download the PSD