There are a few steps I would recommend to keep a healthy neck and prevent pain and stiffness from occuring. I see a good deal of patients with neck pain and there are some common findings in these people that have lead to their problem. Our necks require an integral balance of strength, flexibility and posturing. If people can work on these things on a regular basis, then neck pain would be much less likely to occur.
Maintain healthy posture of the neck by keeping the ears over the shoulders. If the ears go forward it is called a forward head posture and this leads to straightening of the cervical spine (neck) curvature. When this happens we lose what's called a lordosis in the neck, which is our normal cervical curvature. When this curvature is lost then more stress, wear and tear occur to the joints and discs in the neck.
Ensure that your are keeping adequate strength in your shoulders and arms. By keeping up with this strength we can engage in lifting, pushing and pulling activities throughout the day . The shoulders and arms do most of the work and take stress away from the neck. If the arms are weak, we often over utilize the neck muscles, elevate the shoulders to push and pull, and a good deal of pressure is placed on the neck. I would recommend doing exercises such as biceps curls, triceps press, chest fly's and reverse fly's.
Keep the mid to upper back (thoracic spine) flexible. The neck sits on top of the thoracic spine which is the mid to upper back. If proper movement and posturing occurs here then our necks will have less work to do. Many people with rounding of the mid to upper back end up with neck pain, because they cannot keep their necks in proper alignment. When I treat people with neck pain, I always ensure that the thoracic spine is moving properly and that the patient is aware of proper posture at this part of their spine.
Work on balanced rotation movement to both sides. Often times we cannot look over one shoulder as well as we can on the other side, if this occurs there is an imbalance in motion and one side may have more stress on it. So, we want to keep our neck rotating equally to both sides. Try stretching the neck into rotation to the right and left often. If we do things were we are looking to the right more often throughout the day, whether it be at work or during a recreation activity, then looking to the left is going to get tight. So I would ensure that you are creating a balance of movement of the neck to both sides.
Finally work on stress reduction to avoid tensing the neck muscles. Do an exercise called diaphragm breathing to relax your body and obtain good oxygenation to the muscles. I would also recommend to practice meditation, go for walks, and get out into nature on a regular basis.