First, bring your whole body into awareness. Sit on the chair so that you notice the weight on your seat bones, you can let your feet lie flat on the floor, and let your torso balance in neutral over the top of your hips. As you let your hands rest palms up on your thighs, let your hands open and soften. Allow your head to float on top of your long, relaxed neck.
Bring your attention to the head/neck joint—way up high, almost between the ears—and think about allowing this joint to have a little more space. Think about your head balancing easily and delicately. You do not have to hold your head up with your neck muscles if you allow your skull to balance.
Now bring your attention to your breath. Just allow your ribs to move as you breathe—in a three dimensional direction—so that your back ribs have as much mobility as your front ribs.
Next, notice that your skeleton is holding you up, and that you can let your muscles rest in neutral. Allow your arm, shoulder, leg and buttock muscles to rest as you let your bones support you in gravity.
As you bring your hands up to the keyboard, experiment with how little effort is needed. Continue to let your head float gently as you begin working again.