I don't know about you, but I have a lot of trouble with tight neck muscles. Since, as you'll remember, the one really bad injury Annika had involved her neck, I think we should pay more attention to this area. I like this video because it is so simple and requires no special equipment. (Although you might want to sit down when you do it.) And if you have trouble understanding her instructions, they're also shown in closed caption style across the bottom.
Please take good care of your neck. It can really affect your swing... and your health. Just ask Apryl.