Saucha is achieved by the practice of the Yamas which brings Purity in body, thought and word. The abstentions of the Yamas eliminate physical and mental negativity, clearing the way for Purity.
This Purity can apply to personal cleanliness, inside and out. External cleanliness involves bringing attention to one's surroundings and personal appearance. Internal cleanliness is achieved by means of asanas, pranyama and attention to all the yogi eats, drinks or puts into the body. Yogis strives to internally cleanse the mind of hatred, jealousy, greed, pride and lust - negative and destructive forces.
This cleansing of the intellect is achieved by pratyhara and meditation.
Contentment must be cultivated by the yogi in order to achieve concentration. Once a yogi realises one has everything one needs and lacks absolutely nothing, then one experiences natural Contentment. This Contentment helps yogis see they are exactly where they are supposed to be at any given point in time.
Then the yogi is in the here and now. With Contentment the yogi experiences a state of bliss ... a knowledge of happiness.
Tapas is the self-discipline necessary to achieve the yogi's ultimate goal - union with the divine. Self-discipline will eliminate all obstacles to achieving this union with the divine. Tapas must be applied to the body, to speech and to the mind. Bramacharya (Continence) and Ahimsa (Non-Violence) are examples of body Tapas. Making a conscious effort to use words which don't offend and being truthful (Satya) are examples of speech Tapas. Tranquility and mental equilibrium are mental tapas. Tapas will bring a simplicity into the yogic life by focusing on the positive To act in a positive manner, rather than react, is the way of a yogi because it is not possible to control or change others, only to change oneself by means of Tapas. The most obvious and beautiful example of Tapas is to appoint a daily time & space to make Yoga..
Svadhyaya is the study of oneself and education of oneself. This study of oneself is the quest to discover '"Who am I?'" While examining oneself inwardly, the yogi also takes that opportunity to change attitudes in order to accomodate adoration of the Divine. The yogi endeavours to implement a process of 'letting go' of attachment to preconceived ideas and thereby escape the 'maya'. A life of more yoga and less bhoga. Realising that the yogic force within, the Self, motivates one's being, just as it motivates and IS the entire Universe. The I AM. Reciting mantras is a tool for Svadhyaya. Books, literature or even sacred documents may be used by yogis to assist in this quest. However, yogis must always be aware that these tools are only the views of others, which may help yogis see that the answer is within themselves.
Isvarapranidhana means to make all one's efforts/actions for the Absolute. The yogi must relinquish the ego and focus on the Absolute. Then positive energy will flow from the Absolute into all areas of the yogi's life. The Absolute is the source of all power.
It is Isvarapranidhana that enables the yogi to accept whatever circumstances as the will of the Absolute. Devotion can be shown by yogis when offering all efforts to the Absolute during daily Yoga practice...