These are the basic steps in this meditation practice:
Sit comfortably either in chair or cross-legged on the floor with a cushion. Keep your spine erect. (Don’t recline as you may fall asleep.)
Close your eyes, then take a few deep cleansing breaths — maybe three or four.
Notice the sensations of your body as you are sitting. This could be any discomfort or simply pressure on your chair, warmth, tingling, etc. Simply notice these without judgment or anxiety.
Gradually become aware of your breathing. Notice the air moving in and out through your nostrils and the rise and fall of your chest and abdomen.
Allow your breaths to come naturally without forcing them. Allow your attention to rest in the sensation of breathing, perhaps even mentally thinking the word “in” as you inhale and “out” as you exhale.
Every time your thoughts wander (which they will do a lot in the beginning), gently let them go and return to the sensation of breathing. Don’t judge yourself or your intrusive thoughts. Just lead your mind back to focused attention on breathing.
As you focus on breathing, you’ll likely notice other perceptions and sensations like sounds, physical discomfort, emotions, etc. Simply notice these as they arise in your awareness, and then gently return to the sensation of breathing.
When you observe you’ve been lost in thought, detach yourself from the thoughts and view them as an outside witness with no judgment or emotion. Then again, return your attention to the breathing.
Continue with these steps until you are increasingly just a witness of all sights, sounds, sensations, emotions, and thoughts as they arise and pass away.