Where to look when shoulder (head) checking.
Turn you're head 90° degrees in the direction you're moving the vehicle.
Thus, if you're moving the vehicle to the left, you shoulder check to the left by turning your head 90° to the left.
If you're moving the vehicle to the right, you shoulder check by moving your head 90° to the right.
By turning your head 90° degrees, your peripheral vision—which is 180° in most adults—will detect light and movement beyond 90°.
If your peripheral vision detects light or movement, your central vision will be pulled in to determine what is in your blind spot.
See Shoulder Checking videos:
One of the keys to observation on a driver's test is shoulder checking.
Watch the video to be successful!!