Shoulders rolls are a great stretch for the neck and shoulders. Relax your arms and roll your shoulders 5 times in each direction. Get full range of movement, and go slow; don't rush it. You want to roll your shoulders in round circles while looking straight ahead, breathing and relaxing into it.
After you do that, interweave your hands behind your tailbone (knuckles facing down) and gently drop your left ear towards your left shoulder. Stretch to where it feels good. Take 5 deep breaths. Imagine a balloon in the tightest area and that you are blowing it up and releasing tension. Switch dropping your right ear to your right shoulder and take 5 deep breaths to the other side.