This book began as an essay to add some guiding notes to the practice of mindfulness of breathing (ānāpānasati). The intention was to be concise, with the understanding that plenty of meditation manuals are available, as are several thorough expositions of the theory and practice of mindfulness of breathing. However, as this meditation is so crucial, it seems useful to contribute any fresh approaches. And I have noticed that the way I understand and approach mindfulness of breathing is both somewhat different from what I was originally taught, and yet can fit the original sutta presentation.