This standing stretch can be done anywhere, and will offer a deep stretch in the sides of your neck.
Stand with your feet hip distance apart, arms by your sides. Reach both hands behind your backside, and hold onto your left wrist with your right hand. Use your right hand to gently straighten your left arm and pull it away from you slightly. To increase the stretch in your neck, slowly lower your right ear toward your shoulder. Stay here for 30 seconds and then switch sides.