with your stance. the placement of the ball plays an extremely serious effect on the slicing of the ball. when the ball is placed too far the entire stance of the person is spoiled as it makes you reach out to the ball causing your shoulders to go far beyond your hips. this messes up your swing and may even cause you to go off balance. the position of the ball should be about 2-3 inches inside of the left foot of the golfer.
in case you have to play shots on an uneven lie then you have to change your stance, otherwise it is recommended that you assume the same 