Rule 3 of 25 · Chapter I — Before You Move
Set your hands slightly ahead of the clubhead at address so the shaft leans a touch toward the target.
Why this rule exists
Good iron impact has the shaft leaning forward, hands ahead of the ball. Starting in a version of that position means you have less to manufacture on the way down and are less likely to flip the club to find it. A shaft leaning backwards at address invites you to add loft and catch the ground first.
In practice
Let your lead arm and the shaft form close to a straight line down to the ball — a slight forward lean, not a dramatic one. Check it in a face-on video or a window reflection; the grip end should sit just inside your lead thigh with a short iron. Keep the hands ahead without pressing them so far forward that the face opens or the shoulders tilt out of position.
When it doesn't apply
Sand shots and high flop shots are played with a neutral or even reversed shaft position, since you want loft, not compression. Very forward-shafted setups also deloft the club, so make room for a club more of loft than the number suggests.