There are eight point four million traditional yoga postures and that is still only one small aspect of the practice. Specific breathing techniques are another aspect of the practice. One of the most basic and yet beneficial breathing techniques is called Nadi shodhanam which in simple terms means alternate nostril breathing.
A little more detail: Nadi is the passage (little river) through which the breath energy flows and shodhanam (cleansing) refers to the healing qualities of the technique.
To practice nadi shodhanam, place the left hand on the left knee in jnana mudra (press the tip of the thumb and tip of the index finger together), palm turned up or down. The right hand is in vishnu mudra (bend the two middle fingers of the right hand into the palm) or extend the index and middle finger and press them on the ajna chakra (point in between the eyebrows).
The thumb is used to close the right nostril. Begin by inhaling slowly through the left. Then press the ring finger and little finger on the left nostril, lift the thumb and exhale through the right. Then inhale through the right and exhale through the left. Continue at your own pace.
You can also add the mantra "So Hum" and "Hum Sa". Repeating "So" when you inhale left, "Hum" exhale right. "Hum" inhale right and "Sa" exhale left.
Sohum and Humsa have the same meaning " I am that I am". They are powerful mantras to calm and stabilize an overactive mind.
The benefits include: Calming, centreing balancing and cleansing. It nourishes the nervous system and brings a feeling of overall wellbeing.
If you feel stuck or anxious during practice stop.
I do recommend learning directly from a teacher. This practice is generally good for all but that does not mean it's right for you.
Practice daily. 3 rounds a day counts - Eventually you will be able to practice a little longer.