Progressive muscle relaxation is an exercise where you alternately tighten and relax specific groups of muscles. Here's a nice overview:
"Sit in a comfortable chair – reclining arm chairs are ideal. Lying on a bed is okay too. Get as comfortable as possible – no tight clothes or shoes and don't cross your legs. Take a deep breath; let it out slowly. Again. What you'll be doing is alternately tensing and relaxing specific groups of muscles. After tension, a muscle will be more relaxed than prior to the tensing. Concentrate on the feel of the muscles, specifically the contrast between tension and relaxation. In time, you will recognize tension in any specific muscle and be able to reduce that tension.
Don't tense muscles other than the specific group at each step. Don't hold your breath, grit your teeth, or squint. Breathe slowly and evenly and think only about the tension-relaxation contrast. Each tensing is for 10 seconds; each relaxing is for 10 or 15 seconds. Count "1,000 2,000..." until you have a feel for the time span. Note that each step is really two steps – one cycle of tension-relaxation for each set of opposing muscles.
Do the entire sequence once a day until you feel you are able to control your muscle tensions. Be careful: If you have problems with pulled muscles, broken bones, or any medical contraindication for physical activities, consult your doctor first.
1. Hands. The fists are tensed; relaxed. The fingers are extended; relaxed.
2. Biceps and triceps. The biceps are tensed (make a muscle – but shake your hands to make sure not tensing them into a fist); relaxed (drop your arm to the chair). The triceps are tensed (try to bend your arms the wrong way); relaxed (drop them).
3. Shoulders. Pull them back (careful with this one); relax them. Push the shoulders forward (hunch); relax.
4. Neck (lateral). With the shoulders straight and relaxed, the head is turned slowly to the right, as far as you can; relax. Turn to the left; relax.
5. Neck (forward). Dig your chin into your chest; relax. (Bringing the head back is not recommended – you could break your neck)
6. Mouth. The mouth is opened as far as possible; relaxed. The lips are brought together or pursed as tightly as possible; relaxed.
7. Tongue (extended and retracted). With mouth open, extend the tongue as far as possible; relax (let it sit in the bottom of your mouth). Bring it back in your throat as far as possible; relax.
8. Tongue (roof and floor). Dig your tongue into the roof of your mouth; relax. Dig it into the bottom of your mouth; relax.
9. Eyes. Open them as wide as possible (furrow your brow); relax. Close your eyes tightly (squint); relax. Make sure you completely relax the eyes, forehead, and nose after each of the tensings.
10. Breathing. Take as deep a breath as possible – and then take a little more; let it out and breathe normally for 15 seconds. Let all the breath in your lungs out – and then a little more; inhale and breathe normally for 15 seconds.
11. Back. With shoulders resting on the back of the chair, push your body forward so that your back is arched; relax. Be very careful with this one, or don't do it at all.
12. Butt. Tense the butt tightly and raise pelvis slightly off chair; relax. Dig buttocks into chair; relax.
13. Thighs. Extend legs and raise them about 6in. off the floor or the foot rest but don't tense the stomach' relax. Dig your feet (heels) into the floor or foot rest; relax.
14. Stomach. Pull in the stomach as far as possible; relax completely. Push out the stomach or tense it as if you were preparing for a punch in the gut; relax.
15. Calves and feet. Point the toes (without raising the legs); relax. Point the feet up as far as possible (beware of cramps – if you get them or feel them coming on, shake them loose); relax.
16. Toes. With legs relaxed, dig your toes into the floor; relax. Bend the toes up as far as possible; relax.
Now just relax for a while. As the days of practice progress, you may wish to skip the steps that do not appear to be a problem for you. After you've become an expert on your tension areas (after a few weeks), you can concern yourself only with those. These exercises will not eliminate tension, but when it arises, you will know it immediately, and you will be able to "tense-relax" it away or even simply wish it away."
http://en.wikipedia.org/wiki/Jacobson%2 ... Relaxation