Check your distance from the ball with a simple hand test:
With irons, remove your trail hand, form a fist with your thumb extended, and place it between the end of the club and your body — a fist, thumb, and roughly an inch gap is your guide to a consistent setup position.
Stand further away and hinge from the hips, not the knees:
Too much knee bend combined with a narrow, close stance forces an overly upright swing plane, which restricts arm extension through the shot and leads to thin contact — backing off slightly and bending from the hip joint creates the athletic, ready position you need.
Swing plane changes with each club, so your distance from the ball must too:
A pitching wedge requires a more upright swing plane than a driver, which needs a flatter arc — standing the correct distance away for each club allows your swing plane to adjust naturally without forcing the issue.