What most people are seeking normally is an accurate shot, so they assume that means a straight shot. To create the straight shot — a shot without curve — you want to match the clubface up to the path that the club is swinging along. With a square clubface and a square path, a centered strike will result in a straight shot.
More likely, however, we need to slightly counteract our normal shot shape in order to create a straighter shot. Using a plane station, you want to rehearse a swing that would feel like you’re trying to hit a shot shape that is the opposite of your normal ball flight. As a result, you’ll hit a shot that is straighter than your normal shots.