General Points  
In Yoga life even for beginners some common guidelines are as follows: 

• Sex in adolescent age group is considered harmful. Young boys and girls during sex not only exchange positive energies but also the negativities of each other. The body is not fully developed, the emotions are not matured and mind is filled with confusions, which lead to difficulties in adult married relationships.

• Sex is prohibited during menstrual cycle.

• After conception very little or no sex.

•  No sex during intense spiritual practices.

• Sex with multiple partners can lead to sickness.

• No sex or very reduced sex after 50 years of age.

Aparigraha (Non-accumulation) 
This represents non-possessiveness. Not to accumulate what you do not need. Also it implies the idea of not accepting inordinate favors, not be attached to the objects one possesses, not to accumulate more & more material things. First we spend time and energy in accumulation of things that we do not really need. Then we have to spend time and energy in guarding the things that we have accumulated. Thereafter there is the constant fear of loosing them. Consider the colossal waste of time and energy all this involves. An aspirant cuts down his needs so as not to waste his energies. He remains satisfied with what comes to him in the natural course of the working of the law of karma. Aparigraha involves not accepting certain gifts even in normal relationships. It is explained through the fact that a present brings with it all the psychic elements with which it has been charged by the one who offers it especially desires, obligations, which creates a series of debts that cannot be compensated and which put the independence in danger. Through the practice of aparigraha, fear, hate, disappointment, attachment anxiety and sadness are removed. 

Niyama 
Observation of these rules provides the yogi the necessary power in the mind to defeat the misery producing activities and the effects of past bad karma. 

Sauch (purity) 
The word sauch means purity. The word purity is used in relation to our bodies (the vehicles or instruments of the soul). The word body stands not only for the physical body that we can see but also the super physical bodies that serve as the instruments of emotion, thoughts and other spiritual faculties. A thing is pure in relation to a vehicle if it enables the body to serve efficiently as an instrument of the soul at a particular stage of evolution. It is impure if it hinders the full expression of the soul in the exercise of its functions. Purity is therefore, nothing absolute, only functional and related to the next stage of evolution which life is seeking to attain. Purification therefore, means elimination from the bodies those elements and conditions, which prevent them from exercising their proper functions and attaining the goal of self-realization. Purity, though it is functional, depends to a great extent upon the quality of the material of which a particular body is composed. The functional efficiency of