Niyama is the second limb in Ashtanga Yoga.  It means observances, and self-restraint.  There are five inner practices we can follow to maintain moral principles:

-Samtosa is contentment.  Be happy in the present moment.  Know that everything you have, and everything you are is enough.  Be satisfied and content.

-Tapas is a zest for life.  Learn and grow every day, build strength and wisdom.  Develop spiritual practices and be disciplined.

-Saucha is a purity of body and mind.  Take care of yourself, body, mind and spirit, and also take care of your environment.

-Svadhyaya is self-referral.  Practice contemplation and introspection.  Get to know yourself so that you may then know others.

-Ishvara Pranidhana is devotion.  Let go of the ego and embrace a higher source.  Approach life with a sense of gratitude.