Standard approach: Rotate your head through a 360 circle.

Improved: The portion of the rotation where your head is tilted straight back places a lot of pressure on your spine. Instead, perform the stretch by tilting your head to the left and holding it for ten to 15 seconds, then roll it towards your chest for ten to 15 seconds. Finally, lean your head to the right for ten to 15 seconds. You can also stretch your neck by gently turning your head to either side and looking over your shoulder.