This is second step in the eight-fold path of Maharshi Patanjali’s Ashtang yoga. ( other being Yama, Asanas, Pranamaya, pratyahar, Dharana, Dhyana and Samadhi) Niyamas are observances; something that you need to do. These are Do’s in life. They are about our own self. They are five in number.
It is about cleanliness; cleanliness both external and internal. External would mean keeping your body and surroundings clean and putting on clean cloths. Internal cleanliness, which is rather more important is about keeping your mind clean with positive thoughts and keeping your chitta clean from avidya etc Kleshas by Vivek ( discrimination). The logic is simple- “ A clean body can only have a pure soul”.
Santosh ( cleanliness)
It is being satisfied with what you have, not looking for more and more. What one may have is considered to be sufficient to keep one living and working. No doubt, mind craves for more and more but never stops at any particular point, so it is endless game keeping you always dissatisfied. Contentment is absence of any desire for anything physical or otherwise. But it would never mean that we should stop functioning for our growth and advancement. It merely indicates that objects can never be your source of happiness so try to live with what you consider as necessary. The effect of contentment is that one experiences supreme happiness.
Tapa ( austerity)
It is refining ourselves. Making efforts, struggling to achieve something and making our will power strong is talked about here. Nothing worthwhile is achieved in life without struggle. These are the austerities we perform in order to achieve something. They could be in the form of keeping silence, fasting, working with one pointed ness on a particular project, taking vow to get rid of some undesirable habit, whatever you think would make life meaningful is considered here. In yoga it is subjugating your senses, mind and regulating your Prana. That is why panchshikha has described that there is no austerity greater than Pranayama.
It is about studying self and also studying the scriptures. Swami Vivekanand says that the higher the beings that you want to get, the harder is the practice. Reflect continuously about the self- what is desirable, what is undesirable and how to get rid of that undesirable.
It is greatest of all Niyamas. You have taken shelter under the lotus feet of the Lord. You have reduced your I-sense to zero, and thus it is about surrendering to God's will; whereby one surrenders all works to God without thinking of results. The surrender is not a mere mental attitude, it is by opening up to divine light, exposed to the divine light so that old motives and forms are destroyed and transforming consciousness of the divine takes place says Aurobindo. Mere attitude of surrender without a will to change becomes tamasik passivity.
Niyamas are nothing but code of conduct for healthy living. While sauch or cleanliness and tapa are for physical health, the Santosh ( contentment) and Swadhyaya ( self study) are for mental, emotional and social health. If you could follow Niyamas, you don’t need to do any other thing. If you find it difficult to follow all five pick one for physical health that is tapa- शरीर को तपाओ, exercise and fight with all the impurities in your life in the form of bad habits, bad posture, bad manners or anything you want to set right. Decide on small small achievable goals and then move on.
For me one think was, is and shall always remain Ishwar Pranidhan- take shelter in God, in Divine in all sincerity. But you must have complete and unshakable faith in Him. Then all things will fall in place automatically. Ishwar pranidhaan, mind it, doesn’t mean lack of self- effort.