>>2118975That's a bit much.
Obviously, you start with a render. Positioning and sizing the elements is crucial if it's to look 'realistic'. In this image, the red lines converge to the vanishing point. The horizon cuts through EVERYTHING at the same height.
It cuts through the traffic light, so that's about 10 or 12 feet above street level. That's the elevation of the camera. But it also goes through the girl's neck. So, either SHE'S 10 or 12 feet tall or is standing on a platform. Without those construction lines the viewer may not recognize exactly what's wrong, but the scene will look fake.
Blur the boundary between the separate elements slightly to avoid having her look like a cut-out.
Your already recognize that lights and shadows should look consistent, but there are entire books written on photo-manipulation. Read some.