What are the best settings to use with a Yongnuo flash on a Canon 6D for optimal lighting in low light conditions?

To achieve optimal lighting in low light conditions with a Yongnuo flash on a Canon 6D, it is recommended to use a low ISO setting (around 100-400), a wide aperture (around f/2.8 or lower), and a slower shutter speed (around 1/60 or slower). Experiment with these settings to find the best combination for your specific shooting situation.