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

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