A square golf swing is something which a newbie golfer would never use. Forget golfer anyone with a sane mind would say that the club should head right in the direction of the target to hit the target, it may sound reasonable but it is not always right.
Unlike baseball, cricket (most shots) and golf are games in which the player swings the club (or bat) in a vertical circle. In baseball too the bat travels in a circular trajectory, but it is mostly horizontal, but in golf when the club hits the ball the club is traveling along a circular trajectory in a vertical direction.
The mistake most people do, even some accomplished regulars is they believe that their club travels in a straight line for a brief period of time. Which is a huge technical error, and some will forcibly try to alter the flow to give a linear momentum to ball. This in turn will force you to miss the target. Instead the right approach is to accept the fact that the path of the club is circular and bring the club head without any conscious effort to alter the trajectory.
Now a small test of back swing:
You take the club away from the ball, as every coach would tell you (or through basic common sense) take the club straight back. Please a video recording device right behind you while doing so. Then bring back the club to hit the ball. Now rewind and look at the video, you will notice that your backward movement is not straight behind the ball, but a gentle arc. You will again follow the same arc when you bring the club forward to hit the ball.
Now the important thing is to accept that you swing the bat back with a gentle arc, now the most important thing, while bringing the club back to hit the ball imagine that you are targeting to hit ball towards the right of the actual target (assuming you are a right hander). The angle at which you should target the right of the target should be around 30 degrees and not more than that. Just make sure that the club is heading that direction everything else will fall in place, such a shot is called as ‘inside out shot‘. This is the square golf swing and can play a major role in fine tuning your game. You can also follow these 5 tips to get a good golf swing overall