If you’re thinking about recording a relaxation exercise (or a meditation), go for a walk in the park, whip out your phone and record audio of nature sounds (birds chirping, wind rustling, water gurgling, etc).
Here’s a short video showing how…
You could just get your phone out, click record and you pick up some nice ambient background sounds. And if you’re in a wood and you can hear the chirping sounds, you can use that. Or you could record the meditation right there and then without a mat. Just do a 5, 10 or 15 minute meditation, relaxation or yoga class in the middle of forest with no one around with the bird song in the background. It would make a really nice, authentic audio class.