Most golfers think the club's toe should point straight up at hip height going back. To accomplish this, they roll their hands to the inside, which opens the face.
The correct toe position at hip height is tilted slightly toward the target line, so that the club's leading edge matches your spine angle (left). That's square. From there you can achieve a square face at the top, parallel to your left forearm, setting up square impact.
Practice swinging back to hip height without any hand or arm rotation. Here's a swing thought: Keep the logo on your glove pointing out. If the logo points up, you've spun the face open.