What do you need: Safe and quiet space with a place to lay down or sit on in a comfortable position.
What can it help for: Promotes tension release, relaxation for different areas of the body; increases energy level, improves concentration and memory.
N.B. Please do PMR without straining. You do not need to exert yourself, just contract each muscle firmly but gently as you breathe in. If you feel uncomfortable at any time, you can simply relax and breathe normally. PMR shouldn´t be painful or uncomfortable.
Regular PMR practice gets the most benefit.
How much time do you need: Up to 20 minutes.
How to do it?
Position - begin by finding a comfortable position, either sitting or lying down.
Attention - allow your attention to focus only on your body. If you begin to notice your mind wandering, gently bring it back to the muscle group you are working on.
Breath - take two or three deep abdominal breaths, exhaling slowly each time. As you exhale, imagine that the tension throughout your body begins to flow away.
Let´s begin. 
STEP 1 
Now, tightly, but without straining, clench your fists and hold this position for about 5 seconds. 
Release and pause for about 10 seconds.
STEP 2
Tighten your biceps by drawing your forearms up toward your shoulders and “making a muscle” with both arms. You may even visualize that muscle tightening. Hold for about 5 seconds. 
Release, enjoying that feeling of limpness. Inhale and exhale. 
Pause for about 10 seconds.
STEP 3
Tighten your triceps—the muscles on the undersides of your upper arms—by extending your arms out straight and locking your elbows.  Feel that build up of tension. Hold for about 5
seconds.
Release and pause for about 10 seconds.
STEP 4
Tense the muscles in your forehead by raising your eyebrows as far as you can. Hold for about 5 seconds. 
Release. Imagine your forehead muscles becoming smooth and limp as they relax.
Pause for about 10 seconds.
STEP 5
Tighten your eye muscles by squinting your eyelids tightly shut. Hold for about 5 seconds.
Release and pause for about 10 seconds.
STEP 6
Tighten your jaw by opening your mouth so widely that you stretch the muscles around the hinges of your jaw. Hold for about 5 seconds.  
Release and let your lips part and allow your jaw to hang loose.
Pause for about 10 seconds.
STEP 7
Tighten the muscles in the back of your neck by pulling your head way back, as if you were going to touch your head to your back. (Be gentle with this muscle group to avoid injury.)
Focus only on tensing the muscles in your neck. Hold for about 5 seconds. 
Release, feel the weight of your relaxed head and neck sink. Pause for about 10 seconds.
(Since this area is often especially tight, it’s good to do the tense-relax cycle twice.)
STEP 8
Now lift your shoulders up as if they could touch your ears. Hold for about 5 seconds.
Quickly release, feeling their heaviness. Pause for about 10 seconds.
STEP 9
Tense your upper back by pulling your shoulders back, trying to make your shoulder blades touch. Hold for about 5 seconds.
Release and pause for about 10 seconds.
STEP 10
Tighten your chest by taking a deep breath in, hold for about 5 seconds. Exhale, blowing out all the tension.
Release and pause for about 10 seconds.
STEP 11
Now tighten the muscles in your stomach by sucking in. Hold for about 5 seconds. 
Release and pause for about 10 seconds.
STEP 12
Very gently arch your lower back. Hold for about 5 seconds.
Release and pause for about 10 seconds.
Feel the limpness in your upper body, letting go of all the tension and stress. 
STEP 13
Tighten your buttocks. Hold for about 5 seconds.
Release, imagine your hips falling loose.
Pause for about 10 seconds.
STEP 14
Tighten your thighs by pressing your knees together, as if you were holding a coin between
them. Hold for about 5 seconds.
Release and pause for about 10 seconds.
STEP 15
Now flex your feet, pulling your toes towards you and feeling the tension in your calves. 
Hold for about 5 seconds.
Relax, feel the weight of your legs sinking down. Pause for about 10 seconds.
STEP 16
Curl your toes under, tensing your feet. Hold for about 5 seconds.
Release and pause for about 10 seconds.
STEP 17
Now imagine a wave of relaxation slowly spreading through your body, beginning at your head and going all the way down to your feet.
Feel the weight of your relaxed body.
To finish, bring your attention back to your breath. Breathe slowly and smoothly. 
STEP 18
When you´re ready, open your eyes and bring your attention to where you are.