Digital imaging software has drawn photographers to the flames of composite photography in ever increasing numbers, but many overlook the simplest details that separate the good from the bad. When creating model composites, it is important to begin with high quality images. Do not succumb to the belief that everything can be fixed in post-production. Make sure the models and the backgrounds are both beautifully rendered before moving on to the compositing phase by ensuring that both have been captured in the same lighting.
Misaligned lighting-source direction is the fastest way to distinguish between high and low quality composites. If the primary light source is on the left side of the background then make sure that it is in the same location when photographing the model. If there are going to be multiple pictures of the same model used in a single composite, then the lighting source location needs to remain consistent so the pictures appear visually coherent. An example of what to avoid would be to use a background of a sunset matched to several photos that were captured using the camera's onboard flash. The lightings will be in stark contrast, and viewers will be distracted by that instead of the beauty of one's created image.
Another challenge to creating wonderfully believable composites is hair. There are billions of hairs on the average human head and they frequently like to stick out. In the natural world, people perceive this detail but pay closer attention to where the majority of hair resides. It is often easier to trace along the dominant edge of the majority of the hair when the model is being ""cut-out"" of their original photo. However, what this creates is a disjointed effect in the image that viewers perceive but cannot describe. Everyone will notice the missing little fly-away hairs even if they cannot articulate it. To overcome this, one should try to use more of an area around the subject to incorporate these small natural details.
The term model composites can also be used to refer to headshot and Z-card type photographs used in the performance industries, which includes multiple images but they do not typically overlap in the composition.