Clipping Masks are a little-known but very powerful tool in Photoshop for making your composites look realistic. Simply create a new layer above your subject, right-click and select Create Clipping Mask, and anything painted on that layer will show up only where your subject is visible. By setting this same layer to Hue, any colors you paint on it will also change the color of the subject underneath. So, on this clipped layer set to Hue, and with the brush tool, hold ALT/OPTION to sample a color from the subject (in this case, her hair) and paint that color over the edge fringe. This will effectively turn the fringe into our subject’s hair color, and make her hair blend into a new background much more seamlessly.
For a really natural look, sample colors from the new background and paint along the edges of your subject with a large, soft-edge brush to create the illusion of the background’s light wrapping around your subject. It will further place them in the scene with great effect.