Here is a fairly simple relaxation technique:
Lie in bed or on a sufa with your arms extended at your sides, or sit in a comfortable chair with your forearm and hands resting on the arms of the chair. Be sure all ten fingers touch the bed or chair. Fix your eyes on some focal point - a lamp, a picture, or even a crack in the wall - and continue to look at it as long as it is comfortable to do so. Then let your focus blur and let your eyes close and your body relax. Visualize the areas of your body as you coax successive muscle groups into letting go.
When your body is fully relaxed, tell yourself that you will now cound slowly from ten down to zero and that, on reaching zero, you will be very relaxed, very deeply and pleasantly relaxed, more relaxed than ever before.
Need a visual on this one? This is what it might look like from the outside: