Many golfers struggle to get the majority of their weight forward (90% over the lead foot) at impact.

To do this, the hips have to move towards the target. This moves the mass of the lower body forward. This step drill is a great drill I use with some of my students to give the feeling of sitting/squatting to start the downswing and making sure the weight moves over the lead foot at impact.

Another way of saying it would be to keep moving your hips over your lead foot during the swing.

Any swaying away from the target on the backswing is only going to cause inconsistent ball striking.