Which action is not a recommended practice when checking your mirrors?

Relying solely on rearview mirrors is not a recommended practice because it limits a driver's awareness of their surroundings. While rearview mirrors are useful for viewing what is directly behind the vehicle, they do not provide a complete picture of the road and traffic conditions on either side. Effective driving requires the use of side mirrors in conjunction with the rearview mirror to ensure that drivers can fully account for vehicles in adjacent lanes and blind spots.

Using all mirrors helps provide a wider field of vision, which is crucial for making safe lane changes, merges, and other maneuvers. Therefore, while rearview mirrors are important, they should never be the sole source of visual information for a driver, making this choice the incorrect practice in mirror checking protocols.