Now it's go time. The easiest way to photograph a silhouette is to position yourself so that the subject is between you and a bright background, such as the sky or bright artificial lights.

Point the camera directly into the brightest part of the scene and depress your camera's shutter release enough to lock in the exposure. Then, keeping our finger on the partially depressed shutter release, recompose your picture and shoot.

If all goes well, you'll get an inky-black subject, since the exposure was based on the brighter background. If your subject isn't quite silhouetted, you can try again, underexposing the image even more using the exposure compensation control on your camera. In the photo linked here, I silhouetted a child against the sunset.

And in this photo, I spied a bird that simply would not wait for me to walk around the tree for better lighting.