Core principles of muscle relaxation:
- Non-doing: you can’t do muscle relaxation. It is a ceasing of doing. A ceasing of effort.
- There is always a deeper level of relaxation (people underestimate how much they can relax)
Here is a recording of muscle relaxation skills training:
It starts around 6 seconds later. Basically you will be asked to tense various muscle groups in turn, then relax them as deeply as possible.
In general only a few practice of this would be sufficient to develop awareness of muscle tension during the day, then you can just use the cue words (in the recording) to relax any muscle group during exhalation any time of the day, anywhere once you notice the tension. This means that you will not need this guided audio in the long run.