Preview of The Final Result:
Step 1Create a new 2300x2300 px document in Photoshop and fill it with white. Open the desert image and drag it into the white canvas using the Move Tool (V). Use the Free Transform Tool (Ctrl+T) to resize it to fit the size of the document. Place it in the bottom of the canvas.
Step 2Duplicate this layer and flip it vertically (Edit > Transform > Flip Vertical). Move it up to the top of the scene.
Step 3Click the second icon at the bottom of the Layers panel to add a mask to each of the desert layers. Activate the Brush Tool (B) and select a soft round one with black color. Use this brush to remove the sky and hard edges, making them soft and smooth.
Step 4Select two desert layers and hit Ctrl+G to make a group for them. Change the group's mode to Normal 100%. On top of the desert layers , go to Layer > New Adjustment layer > Curves and increase the lightness. On this layer mask, use a soft black brush to reduce the lightness on the top desert and the foreground of the bottom part .
Step 5Make another Curves adjustment layer and decrease the lightness on the foreground of the top and bottom. On the layer mask, paint on the middle background as we aim to add the main light source to this place .
Step 6Add a Brightness/Contrast adjustment layer to increase the contrast of the foreground on the top and bottom of the scene. Paint on the rest to keep its lightness.
Step 7Open the sky image and use the Rectangular Marquee Tool (M) to select the sky only and place it in the space between the up and down desert parts. Set this layer below the desert groups.
Step 8Make a Hue/Saturation adjustment layer to desaturate the sky. Bring the Saturation values down to -84:
Step 9Create a Curves adjustment layer to darken the sides of the sky. On the layer mask, paint on the middle to reveal the light there .
Open the model image and isolate her face from the background using your own method.
Step 11We'll remove some unwanted details on the left of her face (from the viewer). On the model layer, use the Polygonal Lasso Tool (L) to select a part from her right cheek and press Ctrl+J to copy this part on a new layer. Flip this part horizontally (Edit > Transform > Flip Horizontal) and move it to the left of her cheek.
Add a mask to this layer and use a soft black brush to blend this part with the existing skin to hide to trace of the finger.