Add some atmosphere
In the main editor, duplicate the background layer. Use the Burn tool to darken the shadow in the background. To add fog, make sure your Foreground colour is set to black, then add a new layer and go to Filter>Render>Clouds. Next, go to Filter>Gaussian Blur and set the radius high at 83 pixels and apply. Change the layer blending mode to Screen, Opacity 50%. Add a layer mask and use the Gradient and Brush tool to mask out any unwanted bits of fog.