the beauty of arch sitting alone in Photoshop's synthetic lights
Final effect
1, open the background picture, then open the girl photo, use the Pen tool to pick up the girl, you can use any of the tips you feel good, I use the pen tool is to get a better edge, when finished, put the position from the figure below.
2, the scene element already has, our effect is to show so many content, before making the lighting effect, first will make the girl's shadow.
First copy the girls layer, and place it under the girl's layer, then click "Image > Adjust > Hue/Saturation" to set the saturation to-100, press ctrl+t the "Free transform" right click to select "Vertical Flip", in the call "Filter > Fuzzy > Gaussian blur" Set the radius to 4 pixels to soften the edge of the shadow, and then lower the opacity of the layer.
3, add shadows on the back, create a new layer above the girl's shaded layer, use the soft corner brush tool, turn the opacity down, and draw the shadow so that the girl has a shadow on the wall.