While good conduct is not the goal of spiritual life, it does creates a necessary base for deep meditation. Without it meditation ultimately becomes impossible. Therefore it is seen as part and parcel to meditation.
There are the 10 yogic principles of morality called Yama and Niyama. They are 1) Ahimsa,2) Satya, 3) Asteya, 4) Brahmacarya, 5) Aparigraha, 6) Shoacha, 7) Santosha, 8) Tapah, 9) Svadhyaya, 10, Iishvarapranidhana.
These 10 point were found to be in all those who had reached the goal of meditation, ie Self Realisation. Therefore they should be seen as guidelines to follow, understanding if you could followed them perfectly you would not need to meditate. This is because it means you are fully enlightened! Nevertheless you need to do your best and along with regular meditation, each point will eventually become second nature to you. The goal, for example, is not to never steal but for the thought to steal should never enter your mind.
1.Non-injury in thought, word and deed. Not to consciously intend to do harm to anyone or thing unless it is in self defense or self preservation. For example when deciding what life to live off we should choose the lower forms like plants over animals. However if there is only animals to eat then eat animals. But for most people there is no reason to kill animals for food because there are plenty of fruit, vegetables, grains, legumes etc to live off.
2. Benevolent truthfulness. To be truthful when we speak, however not if violates the first principle on non harm. If speaking factually is going to offend someone then generally it is not good to do so. But in most circumstances being factually truthful is necessary.
3. Non-stealing. Not to take anything that does not belong to you, even in thought. It also means not to deprive someone of they due. For example not paying for a train ride.
4. Seeing Cosmic Consciousness in everything. This means to view everything as an expression of your higher infinite self and not as merely a mundane object or person.
5. Non-indulgence in non-essential luxuries. Generally it means to live simply and to avoid luxurious living.
6. Cleanliness: Physical and mental purity. Keeping your body and environment clean as well as your thoughts. Avoid mean and selfish thoughts.
7. Contentment. Learn to be content with what you have, presuming you have the basics of life, ie adequate food, clothing, medical care, housing and education..
8. Selfless service. Be prepared to undergo some discomfort or inconvenience in order to help others less fortunate than yourself.
9. Understanding of spiritual truths.
Daily reading of books that remind you and inspire you towards your spiritual goal. It also means to understand their inner meanings.
10. Focus and surrender. To keep your mind on your spiritual goal (Self) always as your base in life, regardless of how good or bad it is, while by your meditation moving with surrender and speed to that Supreme Goal.