Instructions
Place a bright adjustable spotlight or directional lamp behind your subject, facing the light towards the camera. Stand the subject directly in front of the light fixture so it is not visible in the photo.
Adjust the height and angle of the light to create the desired effect. For example, placing the light low and angled up will create a rising glow, while placing the light slightly to the side will create a sheet of light that grows from one side to the next.
Take the photo. When placed properly, the subject of the photo will become a black shape with facial or other details disappearing. Other features, such as hair, will be finely outlined. Experiment with the placement or movement of the subject. For example, take the shot when the subject is jumping or swinging her hair for a dramatic effect.
Use the sun as a source for the backlighting, placing your subject's back toward the sun and shooting from the front. The lower the sun is in the sky, the more glow there will be.