This should leave on side of the face in shadow but keeps a triangle of light on the cheekbone and eye.
To create Rembrandt, lighting, the subject should be turned slightly away from the light. The light should be above the top of the head. Move your main light around the subject until the shadow of the nose is touching the shadow of the face. This should leave on side of the face in shadow but keeps a triangle of light on the cheekbone and eye.