We covered this in a very interesting and informative video before with a competition shotgun shooter.  It may be useful to go back and watch his video.  He’s a winner, so what he says is worth listening to.

This analysis at Shooting Illustrated adds to the discussion.

In general, dedicated shotgun-sports shooters (trap, skeet and sporting clays) take on a feet-close-together, straight-legged, weak-leg-forward stance, with the toes pointing 45 degrees to the target, 95 percent of the weight over the front foot. Such a stance allows wingshooters to swing the shotgun by more-or-less pirouetting on the front foot while using the toe of the rear foot as a rudder for balance. This tall, elegant stance is deceiving, because while it doesn’t look aggressive, most of the shooter’s body weight can be thrust into the shotgun at the shot, thereby counteracting the forces of recoil. However, there are obvious reasons why this stance isn’t the most practical for home defenders.

[ … ]

Some military and law-enforcement personnel are trained to shoot a shotgun much like they do a carbine, which is to say their feet are square to the target, shoulder-width apart, toes pointed toward the target, torso square to the target but leaning over slightly so the weight is divided 50/50 over the balls of each foot. This allows operators to maximize peripheral vision and to walk and move in any direction. The squared-chest orientation maximizes body armor’s protection. For most civilian home defenders, however, this stance can be disastrous.

First, most home defenders do not wear body armor. Second, a shotgun loaded with 00 buck has up to 10 times the recoil of a 5.56 NATO carbine, so recoil is a real issue. For all but the biggest, brutish shooters, three shots in succession from a square stance can rock a shooter so far backward that they may fall. (Try it for yourself.) I believe this stance was dogmatically taught to some military types to conform to other curriculum being taught at the time, such as dynamic entry, where moving smoothly and facing the enemy was paramount. These days, however, I see more shotgun-savvy military and law-enforcement shooters adopting a slightly more staggered, hybrid stance of 55/45 (front foot/rear foot) weight distribution. Even so, they keep the torso square to the target as much as possible.

[ … ]

The preferred shotgun stance of professional 3-gun shooters is offense-oriented. Most of these shooters assume a staggered stance where one foot is in front of the other, knees slightly bent, feet shoulder-width apart, torso bladed 40 degrees and bent forward at the waist so that 70 percent of their weight is forward. From this position, they can run, stop and fire multiple times while absorbing recoil and mitigating muzzle flip so they can get the maximum number of shots on target in the least amount of time.

However, there are a couple of significant differences between pro 3-gunners and home defenders: First, 3-gunners don’t have to consider retreating. This enables them to commit more to a weight-forward stance geared for shooting quickly, instinctively and accurately. Additionally, 3-gunners must focus on shooting 10 to 15 shots as fast as possible, mandating their weight be aggressively forward. But, this high-volume “running and gunning” is unrealistic for home defenders.

So then, the best stance for most home defenders—one that promotes a compromise between fast and accurate shooting while maintaining great balance and mobility—is one where the stance is slightly staggered, with the toe of the right foot in line with the heel of the left, feet slightly more than shoulder-width apart, toes pointing 30-degrees to the target, knees bent, chest slightly bladed 25 degrees and the torso bent forward at the waist so 65 percent of the weight is over the balls of the feet. However, during the actual shot, you may find that more weight should be shifted (shotgunners call it “throwing your weight”) forward as much as 80 percent to counteract recoil before being shifted back as soon as the recoil impulse is finished.

But, people, circumstances and shotguns are all a little different. The most important thing is to find and develop a shotgun stance that works best for you. Tactical guys say squared, wingshooters say 90-percent-weight forward, 3-gunners say bladed; I say use what works for you.

I don’t think it’s possible to stay “squared” (aggressive plates forward) and get off quick multiple shots with a 12 gauge shotgun on target.

I think he’s essentially saying what our professional shotgun competitor said in the video.  But it all requires practice.