Look over shoulder
Turn your head slowly as far as you can to one side, then the other
Shoulder roll
Shrug your shoulders up towards your ears, then circle them back and down.
Chin nod
Standing or sitting up tall on a chair with the back of your head resting on the wall, slowly nod your head forwards closing the gap between your chin and breastbone, but keeping the back of you head in contact with the wall. Relax then repeat.
Chin tuck
Standing or sitting up tall on a chair with the back of your head resting on a wall, pull your chin in so that the back of your neck straightens and gets longer and the back of your head slides up the wall slightly. Relax then repeat.
Image credits: Physiotec