What is the best way to achieve a Rembrandt lighting setup for portrait photography?

To achieve a Rembrandt lighting setup for portrait Photography, position a single light source at a 45-degree angle to the subject's face, slightly above eye level. This will create a triangle of light on the cheek opposite the light source, with a small triangle of shadow under the eye on the same side. Adjust the light intensity and distance to control the contrast and shadows for a classic Rembrandt lighting effect.