Photographing Silhouettes - The Skills to Create a Simple Image

When we photograph a sunrise or sunset (particularly on auto exposure) we often end up with a silhouette. This is because our camera exposes for the bright background and the foreground goes to black.
This gives us a clue about how to photograph silhouettes. We shoot our subject against a bright background.
If we have a lot of light on or in our background and little or no light on our subject, we get a silhouette.
Outdoors we can shoot our subject against a bright sky and keep our subject in the shade. Shooting from a low angle to isolate the subject will often work better.
Indoors we can place our subject in front of a lit wall with no light on that subject and simply expose for the lit wall.
When we shoot silhouettes we are working with less visual clues for the viewer to recognise our subject. There is no light on it to show detail, there is no colour either, so we need to orientate and place our subject in a way that it is recognisable to the viewer.
We are simply working with shape to achieve our result.
This often means, for humans and animals, having their face in profile. This shows the individual characteristics of that particular subject and makes it recognisable.
With inanimate objects it means shooting them from an angle that shows a familiar profile or a particular shape.
When posing people we most importantly need to shoot their face in full profile. Make sure that there is no hair or clothing to interrupt that clean facial profile.
With body posing, it is important to show the shape and curve of the figure (male or female). Arms often interrupt the clear shape of the figure so separating them from the body (visually) is often the key.
Try a variety of poses but make sure before pressing the shutter that you have that clean clear facial profile.
Sometimes it may be difficult to achieve a completely black subject particularly on a dull day or in a well lit room. Trying a different location or a different time of day can often achieve better results.
A little tweaking of contrast in post production can also help
A silhouette simplifies the image to it's very basic elements. It can be a powerful statement about your subject or simple add some emphasis to a great background.
Either way, silhouettes require a minimum of equipment and can be stunning when done properly.