I’m not sure. I just do. And every morning that I wake up breathing, I am grateful. I guess that’s how I breathe, with gratitude. No special techniques, sorry, just continuing to be grateful to do so. I suspect this one will be modded. Sorry. I noted it and disregarded it.

Learning to breathe is important part of swimming, which I do a lot of. There’s a technique that all swimmers learn. But out of the water, I just breathe like everyone else, pretty unconsciously.

I learned to do deep breathing while I was in therapy, and I use it to try to quiet my mind sometimes. Mostly while trying to fall asleep, or to attempt to ward off a panic attack. I breath in deeply, slowly, through the nose, letting my stomach (not my chest) rise, to a count of four (or eight, it depends). Hold it for a count of 4 (or 8), then release it slowly, through my mouth. Wait for a count of 4 (or 8), and repeat. I don’t have any set number of complete cycles, I just go until either I’m calm/quiet or I realize it’s not going to work.

I am AWFUL at breathing. Both my parents smoked like chimneys and when they quit I started smoking. I finally quit when I was 30 but had smoked for 20 years by then.
I have started doing yoga and have realized that I have a long way to go to learn to breathe. I grunt and hold my breath to much, and although I’m pretty good at controling my exhale with my mouth, I have practically no control with my nose.
My hope is, that as I continue my yoga practice, I will get better at Pranayama, and maybe breathe well by the time I’m 80.

I learned some breathing techniques in yoga and can fill one lung and not the other. I also did sectional breathing where you breathe deeply into your tummy, then more shallow into your chest then very shallow into your shoulders. It turned out that this is one of the two things in yoga that I had any kind of aptitude for. The other being balancing on one leg.

I’m just one of a long line of mouth breathers in my family. I tried breathing through my nose but my nostrils kept getting in the way.

For following explanation, by breathing, I mean, inhaling and exhaling through nose or nostrils, and not through mouth.
In Sanskrit language, the practice is called Pranayam
It is made up of two words, Pran(a) and Ayam(a). Pran means spirit, soul, and ayam means something like exercise or such practice.
Put simply, it is exercise of breathing to increase capacity and power of lungs, feel at peace, relax, etc. It is done in four stages as below.
1. Inhale : Breathe in slowly.
2. Hold your breath : Neither inhale nor exhale.
3. Exhale : Release your breath slowly.
4. Hold your breath : Neither inhale nor exhale.
The four stages are carried out in some proportion as @augustlan said. I don’t remember. Ah, you may refer this site : http://www.feelingsoulgood.com/index.php?id=5

In addition to physical benefits, there are many other benefits too, like mental benefits (feeling calm).
Swimmers or deep water divers must be trying breathing control.
It can also be used as a tool for concentration. Notice, focus or experience the air moving in and out of nostrils, touching skin inside, hair in nose, etc. After some time, you will be good deal concentrating.

Edit : in this exercise, we are supposed to take in air in lungs, so that lungs rise. Doing this may qualify it to call as exercise.
Breathing naturally or unconsciously, air is taken in and stomach rises, as you may notice while others are sleeping (sleeping dogs, for example). It is used by body for relaxing.

There are lots of meditation techniques that involve conscious manipulation of the breath, but in my own practice I’ve found that it’s better to abandon technique altogether. I position my body so that the front of the torso is open (i.e. chest and belly forward, head high) so that there’s plenty of room for the belly to expand with the breath.

Having done that, though, I don’t make any effort to breathe a certain way. All of my effort goes into being aware of the breath, seeing clearly how it is, but without attempting to control it. I find that just bringing this accepting awareness to the game transforms the breath over the period of sitting. It may start off shallow, chesty and rapid, but gradually move down into the belly and slow down—again, all without me trying to change anything about it.

This approach works better for me because it takes me out of the judgmental mindset where I’m constantly trying to see if I’m breathing “right” or “wrong”, and removes the controlling “I” from the picture.

I know it sounds strange, but controlling my breathing a certain way helps me last longer during sex.

Hatha yoga practices should always be taken on with extreme safety and caution and always learned gradually and under the guidence of an instructor. It can be dangerous if you attempt to try it and do it wrong.

@Blackberry It’s not strange at all… You’re just smart. There is also a pressure point on the bottom of your foot and a spot inside your belly button that can make climax last for a LONG, LONG time comfortably in accordance with said breathing.

If I’m awake then I’m a nose breather but when I sleep, I’m an all out mouth breathing snorer.

I have learned breath control techniques for my singing. In my everyday life I tend to be a nose breather.

My breathing is based on my body’s needs. I never have to think about it nor do I monkey with it. My autonomic nerve system knows what to do depending on what my sympathetic and parasympathetic nervous systems tell it. Generally speaking at rest I breath slowly through my nose (mouth shut) but as my activity raises my breathing rate increases as does O2 and CO2 gasses exchange though out my body’s capillaries and lung tissues. I’ve noticed that during periods of very high physical activity that suddenly my breathing rate will increase for a short while (to catch my breath) and then drop back down to a lower level and then jump back up as needed. It is almost like at a certain exertion level my breathing is hooked up to a thermostat-like device. At times such as that I keep my mouth wide open (and even stick my tough out a little to make the airway larger) and breath though my nose and mouth.