Lie down on the floor and place some books under the bump at the back of your head, not touching the neck. You should have enough books so that your head is not falling back creating an excessive curve in your neck. If you feel compression in the front of the throat, you have too many books. Place your feet hip distance apart, and bent up in what we call semi-supine position, about a foot away from the buttocks. Adjust the feet slightly so that you are not gripping to keep your knees from falling. Rest your hands on the abdomen or pelvis with the elbows pointing away from the body.
This is the position of maximum length for the spine: the knees bent up provide length through the low back and the head resting on the books creates a gentle traction through the cervical spine. In the upright, these curves are often compressed so lying down in this position reverses that wear and tear. It helps to rehydrate the discs that are between the vertebrae which lose fluid due to the pressure of gravity.
Stop any desire to fidget or fix yourself to get comfortable. Just give yourself a few moments to notice what is going on. Simply lying down like this and noticing yourself without doing anything is of enormous benefit. Notice the breathing to help you quiet busy thoughts and to bring you into the present moment, allowing the concerns of the day to fall away.
It is recommended to do this exercise 20 minutes per day.