For any of the following exercises find a comfortable and quiet place to sit or lie down (standing is also an option). All of them may be practiced at any time of the day (an especially favorable time is when you wake up or just before falling asleep). Importantly, avoid engaging with any deep exercises right after your meal. Devote yourself to everyday training, once or twice a day for 10 to 30 minutes. Make an effort to set a time that would be the same every day:

in that way your exercising will feel like a ritual and will help you establish it as your new beneficial habit.

Start bringing awareness to your breathing, notice the rate and depth without interfering with it; just observe and do not judge (criticizing it will add tension to your body). Take a normal , and then try to take a deep slow breath; observe the difference between the two. What is the feeling each breath evokes? Switch between normal and deep breaths for several times. Always breathe in through the nose with the mouth closed; choose what feels more natural to you (through the mouth or nose) for breathing out. Let all the thoughts, emotions, experiences, body sensations, smells, sounds come and go; do not follow them, just bring your attention back to the breathing itself (apply that throughout the whole duration of the exercise).

For a beginner, it might be useful to have one hand placed on the abdomen (below the belly button) during the whole session. The hand rises with each inhalation and falls on exhalation. Let the abdomen expand fully when breathing in and empty it completely when breathing out. Do not try too hard and do not struggle; just try to relax and enjoy. Close your eyes for less distraction.

As soon as you feel comfortable and confident with your abdominal breathing, proceed with one of the following exercises. You may combine a couple of them during the same session (e.g. 5 to 10 minutes for each exercise).
Coherent breathing. The purpose of this exercise is to breathe at the rate of five full breath cycles per minute (average optimal breathing rate). Make the inhalation and exhalation equal (count slowly to five for each breath). It might be a difficult task for a beginner, however you may start by counting to three (for four breath cycles), eventually increase the count to four (another four cycles), finally count to five.

Note that just 10 to 20 minutes twice a day practice of coherent breathing may maximize the heart rate variability because it is associated with a healthier cardiovascular system, a more balanced and stronger stress-response system.

The focus here is to create resistance to the flow of the air. For example, raise the lips as if you were trying to make a duck face, or place the tip of the tongue against the inner side of the upper teeth. Another example would be to hiss like a snake through your clenched teeth, or try to tighten the throat muscles. You could also use an external object (breathe through a straw) etc. Note that breathing out through the nose instead of the mouth creates more resistance. All musical sounds created by contracting vocal cords are also a form of resistance breathing, therefore singing or chanting could be a choice as well.
Experiment and seek what suits you best. Continue with resistance breathing for as long as you enjoy and you feel comfortable.

Breath moving. This exercise could be imagined as an internal massage. It is a combination of abdominal breathing and the technique of visualization; a guided imagery.
During every inhalation imagine and move your breath to the top of your head and with every exhalation – to the base of your spine, perineum, or the sit bone. Continue for at least ten cycles.
When you feel at ease with both, the breathing and the ‘breath moving’ imagery (inhale – top of the head, exhale – sit bone), extend the visualization technique, e.g. imagine every time that you are breathing in as a cleansing, purifying essence that brings harmony and health. Equally picture every time that you are breathing out as a way of carrying any worry, pain, illness, fear or sadness far away. Use your imagination.
Continue for another ten cycles.

Complete natural breathing. Respire deeply and slowly, only through your nose. On inhalation, fill the lower part of the lungs, then the middle part, finally the upper part. Hold the breath for a few seconds. Exhale as slowly as possible emptying firstly the upper part of your lungs, then the middle, lastly the lower part. Relax your face, abdomen, and chest. Continue this pattern for 5 to 10 minutes.

Humming or vibrating breath. Use the same pattern like you did in the previous exercise (complete natural breathing. Fill the lower, the middle, and then the upper part of the lungs by inhaling. Do not hold the breath. On exhalation, make a ‘hum’ sound and keep it for as long as possible. Pull the stomach muscles in, while continuing making the ‘hum’ sound. Relax the whole body. Start over again and keep this pattern for up to 3 minutes.

Chinese breath. This exercise is not a form of deep breathing; however, it is really effective as a stretching exercise. Take three short breaths through the nose without exhaling. On the first intake, lift both arms straight in front you at the height of your shoulders; during the second intake – open the arms out straight to the sides still at the height of your shoulders; third intake – lift them straight over the head. On exhalation (through your mouth!), move the arms in an arc back down to the sides. Repeat for 10 to 12 cycles.

NOTE: If at any point of performing these breathing exercises, you feel dizzy or somehow uncomfortable, simply stop, and relax. Do not fear or hesitate to start again.