The Putting Stance varies from
person to person.
A good standard to adopt is a shoulder-width stance that is square to the target line with your feet facing forward, and your weight evenly distributed.
The conventional Putting Stance is shoulder-width, feet parallel to your aimline, and with your toes pointing straight ahead.
In other words, your feet are lined up with the other flow lines of shoulders, forearms, hips, and knees.
When you adopt an open (left foot back) or a closed (right foot back) stance, you run the risk of your putter path following a line that is parallel to your toe-line, and not your aimline.
If your feet are splayed and not pointed straight ahead, it is easier to rotate your body instead of moving it in a plane parallel to your aimline.
Quote from Dave Stockton "In putting you don't aim with your feet... You aim with your eyes and the clubface. Thus, I like to open my stance slightly, pulling my left foot an inch or so back from the target line."
It is important to keep your lower body quiet when you putt.
The legendary Arnold Palmer putted knock-kneed with his toes turned inwards to stabilise his lower body.
Movement increases the difficulty of squaring the putterface at the moment of contact. When your stance is too narrow, your centre of gravity can sway back and forth.
The width of your stance is a matter of judgement and comfort. Nevertheless, your stance should be of a width that it anchors you and prevents any swaying.
Some golfers will widen their stance if the wind is blowing strongly. By widening your stance you can get your knees and ankles outside of your hips so that your legs slant slightly inwards (The Eiffel Tower effect).
Your body should be in a balanced position over the ball.
A neutral position will see your weight evenly distributed on both feet. Your putting stroke will bottom out in the centre of your stance.
Distribute Your Weight
Some golf teachers prefer that your weight slightly favours your left foot (60%) in order to counteract any swaying motion. This will have the effect of moving the bottom of your stroke further forward in your stance.
It will then be necessary to move your ball position more towards your left instep so that your putterface still contacts the ball in an upward direction.
Your weight should be on the balls of your feet rather than on your heels or toes.
If your weight is either too far back on your heels or too far forward on your toes, your putter path will tend to follow the direction that your weight is tilted rather than that of your aimline.