If you find that your neck gets stiff, you might already be doing this exercise. It’s a nice easy one that you can do when you’re stuck at your desk or waiting for the microwave to finish.
Sitting or standing, slowly take your head in a circular motion. This shouldn’t take much effort as your neck should be pretty relaxed. Depending on comfort, you may want to move through the full 360°, or stick to 180°. I advise my patients that if there are any points in the movement that feel especially stiff, to go over that spot a few times. It’s not unusual to hear some clicking from the neck during these movements. If this is uncomfortable, stop the exercise.