Meditation 101

Now how is mindfulness of in-and-out breathing developed and pursued
so as to be of great fruit, of great benefit?

You may find the following basic meditation technique helpful. It is called anapanasati or "awareness of breathing". It is intended to help you reach a restful and alert state of mind called samatha, or "calm abiding" (Tibetan: Zhiné). It is said that this technique was taught by Gautama Buddha himself in the fifth century BC, and was written down in the first century BC in the Pali canon^[*].

There is the case where one, having gone to the wilderness,
to the shade of a tree, or to an empty building,...

The general principle is to choose a place that is quiet, free of distracting activity and noises, and physically safe. Turn off the electronics and park your tractor.

... [one] sits down folding one's legs crosswise,
holding one's body erect, and setting mindfulness to the fore.

If you can comfortably maintain a cross-legged posture such as the lotus position for extended periods, then the ground or floor could be a good choice. Even then, a mat and cushion are very useful.
If you are more comfortable on a chair, it should be straight-backed and level, at a height where the seat does not cut off circulation when your feet are on the floor.
As Gelek Rimpoche (quoting Allen Ginsberg) said, "If the ground is around, sit on the ground; if the ground's not there, sit on a chair."
When sitting in a chair:
- Your feet should rest comfortably on the floor.
- You may find it more comfortable sometimes to cross your legs at the ankles, but never at the knees -- your leg may go to sleep -- also, this creates asymmetrical stress on the lower back. Try it and see.
If physically possible, you should sit erect with the back straight from the base right up to the top of the head. This keeps the spinal cord straight, which is the easiest and lowest-stress position to maintain. Don't lean back or slouch forward.
To help keep your shoulders erect, it helps to sit with your hands in your lap near to your torso with one hand cradling the other.
The most relaxing position for the hands is to touch the thumb tips together in a circle.
Your jaw should be relaxed, without clenching the teeth.
Your tongue should be resting on the alveolar ridge behind the top front teeth.
Your lips should be closed so that breathing is through the nose if possible.
Your eyes should be lightly (not tightly) closed and focused at a point at the level of your nose and about an arm's length in front -- this helps in "setting mindfulness to the fore."

Always mindful, one breathes in; mindful one breathes out.
Breathing in long, one discerns, 'Breathing in long';
or breathing out long, one discerns, 'Breathing out long.'
or breathing in short, one discerns, 'Breathing in short';
or breathing out short, one discerns, 'Breathing out short.'

Just breathe in and out, through your nose if possible, slowly and naturally.
Pause and relax after each in-breath and out-breath, but don't hold your breath so long that you have to suck it in or blow it out.
Unless you have a head cold or allergy, your breath should not make much noise.
On the in-breath, notice the cooler air moving in through your nose, down through the air passages and into your lungs.
On the out-breath notice the warmer air moving out in the opposite direction.

One trains oneself, 'Breathing in sensitive to the entire body.'
One trains oneself, 'Breathing out sensitive to the entire body.'

Notice how the body accomplishes the in-breath by raising the ribs and lowering the diaphragm, and the out-breath by lowering the ribs and raising the diaphragm.
You may also notice your heart beating, especially at the pauses between breaths.
Notice sensations of heat, cold, and touch on your body.

One trains oneself, 'Breathing in calming bodily functions.'
One trains oneself, 'Breathing out calming bodily functions.'

Are your teeth clenched? If so, just let your jaw relax.
In the same way, check the muscles of your body from top to bottom, relaxing them wherever you find tightness.
Check the muscles in your neck, your shoulders, your arms, your hands. Check your upper and lower back, your buttocks, your thighs, your lower legs, even your toes(!), relaxing wherever you find tightness.

One trains oneself, 'Breathing in sensitive to mental functions.'
One trains oneself, 'Breathing out sensitive to mental functions.'
One trains oneself, 'Breathing in calming mental functions.'
One trains oneself, 'Breathing out calming mental functions.'

Notice how sensations of seeing, hearing, taste, smell, and touch arrive, and how you perceive them by naming them and how you automatically attach feelings of pleasure, discomfort, or indifference to them.
Similarly, watch thoughts arise and watch them fade away (this is called "cultivating the witness"). Whether they are disturbing or pleasant, don't chase after them or let them drag you around; just watch them rise and fall, just as you are watching your breath.
If your mind starts to fill with distracting thoughts, you may find it useful to count the breaths in cycles of 3 in/out breaths. This brings your attention back to the breath and the body, and leaves you relaxed, yet alert to whatever arises.
Paying attention to the body can also help you find out when you are becoming overly agitated. For instance, if you notice symptoms like your heart beating faster, heat rising in your face, and your breathing speeding up, just returning your attention to the breath can help you overcome this agitation.

Once this level of calm and relaxed attention becomes familiar and habitual, you will find yourself increasingly able to return to it, even in the most stressful situations.

[*] The cited verses are taken from the
Anapanasati Sutta: Mindfulness of Breathing (MN 118 [1-4,7,8]).
Translated from the Pali by Thanissaro Bhikkhu.
They have been edited for gender neutrality and ease of comprehension.