"Game Shooting: A Textbook on the Successful Use of the Modern Shotgun," 1955
The Churchill Method proposes an upright stance with the feet placement almost as though you're driving. The right foot is angled about 40 degrees to the right (on the gas pedal) and the left one (on the brake) is point almost straight head. The gun stock is tucked under the armpit, with the muzzles tilting slight upward at the approximate elevation one anticipates the bird will fly, providing a full view of the field.

Helps to be short and with no neck