Rule 1 of 25 · Chapter I — Before You Move
Aim the clubface at your target first, then build your feet, hips, and shoulders parallel to that line.
Why this rule exists
The face sends the ball; your body only influences where the face points at impact. If you set your body first and then twist the face to match, you have built a conflict into the swing, and your hands will try to solve it mid-downswing. Aim errors also disguise themselves as swing faults — a pull that was never a pull, a slice you keep trying to fix with grip changes.
In practice
Stand behind the ball, pick an intermediate spot a couple of feet ahead on the target line, and set the leading edge square to that spot before either foot is planted. Then place your feet, hips and shoulders on a line parallel to it — not pointed at the flag, which would aim you right of it for a right-hander. Lay a club on the ground on the range once a session and check that your feet actually match what your eyes are telling you.
When it doesn't apply
When you are deliberately curving the ball around trouble or playing a slope, the face and body are meant to disagree — set them for the shot shape you want, not square. Off a severe sidehill lie, foot placement is dictated by balance first.