Constructive rest is a simple but very beneficial activity that you can do at home. It takes no special knowledge or skill, just 10 - 20 minutes of your time each day.
You will need a number of paperback books (thin ones are better than thick) and a space on the floor that is comfortable to lie on (carpeted floor should suffice). If you only have hard floors then use a mat or folded blanket.
Stack the books so that they are around 5cm high. Lie down on your back with your head resting on the books and knees bent so that your feet are flat on the ground.
You should be comfortable, if not you may need to adjust the height of the books or add more padding on the floor.
Don't expect anything to happen immediately in response to these thoughts. Gradually muscles will release in response to gravity and the contact of the floor.
Stay here for around 10 minutes, pay attention to what you can see and hear and keep returning to allowing your back to soften onto the floor and release your neck so that your head is supported by the books.
After a while you might like to include your shoulders and legs into your thinking. See if you can release the muscles of your leg, without them falling in or out. As your back releases, think about releasing your shoulders wide, so that they gradually grow away from each other.
Get up slowly, thinking about each movement before you carry it out. I suggest starting by rolling over, leading with the eyes, head, arm then leg.
Notice how you use the muscles of your head, neck and back during this process. Ideally some of the muscular release that occurred when lying down will still be present when upright. When you notice muscles contract as you come to upright, considering whether that muscular action is really necessary. By being curious you will begin to gain more control over your posture and movement.