By now, I have collected a number of recordings that work well. (One did not: It began, “Before going to bed, take some time to make sure that everything you need to do is done.” Oh. No sleep for me then.) The precise details of effective recordings vary. One begins: “This guided meditation will teach you to use distraction itself as a source of relaxation. Begin by taking stock of your body. …” Another intones, after some preamble: “Simply allow your breath to come and go of its own accord. This is the observation phase of the breath surfing technique. The next phase of breath surfing is the activation phase. In the activation phase, you do something. With your thumbs.”

That might sound kooky. But if you follow along you may discover, as I did, that these recordings can guide you into a state of deep relaxation. Unhurried breathing, as yogis have known for centuries, is an effective way to calm the nervous system. Body “scans” — where you lie on your back with your eyes closed and focus on your toes, your ankles, your calves, knees and so on, until you reach the crown of your head — are also powerful ingredients. If you pay close attention, you will notice that as you scan your body, your eyes move around, “looking” at each body part in turn. These tiny movements help the muscles of the eyes to relax.

The breath surfing technique depends on making sequences of movements that gradually become smaller and smaller until you just imagine them (though by that time, you will probably be asleep). To do this, you lie on your back with your hands on your chest. As you breathe in, you very slightly lift your thumbs, and as you breathe out, you allow them to relax back down. Gradually you make the movements more and more minute, until they are just an idea.

Over time, I’ve learned that as long as the narrating voice is soothing and quiet, most guided visualizations or slow breathing practices will induce relaxation.

I’m not alone in advocating these methods. The United States military has drawn on yoga nidra, a guided meditation process that includes body scans and unhurried breathing, to treat veterans with post-traumatic stress disorder and to help them sleep better. Not everyone is willing to try something new: Some of my insomniac friends are wedded to their habits, and stubbornly resist using a recording to relax. But most of those who do try: zzzzzz.

Olivia Judson, a scientist and the author of “Dr. Tatiana’s Sex Advice to All Creation,” is writing a history of life and Earth.