This is almost a complete outline of the essentials of the practice of Yoga. But, when you
actually begin to practice it, you will find it is very difficult. So, you have to be very honest in your pursuit. Swami Sivananda taught us that Sadhana has three prongs, like a Trisula (trident):

A Daily Routine of Practice. Have a fixed procedure of practice every day. One must keep fixed hours and discipline his personality. In daily routine, three items should be very important:

(a) JAPA - chanting some Mantra over and over to maintain the same consciousness (this is often useful when meditation is difficult);

(b) STUDY - reading scriptures or texts on Yoga, e.g. Upanishads, Bhagavadgita, The
Sermon on the Mount, The Imitation of Christ;

MEDITATION - should be performed at a fixed time and in a fixed place every day (you should not change the place); face the same direction daily (either the East or the North) and sit in the same Asana (i.e. posture) every day.

An Annual Resolve. Vow to give up bad habits like harming or hurting others, telling lies, and incontinence; these three must be given up (slowly) by degrees. Ahimsa, Satya,
Brahmacharya are to be practiced. If you break this resolve, you should fast one day.
Because of the fear of fasting, you will be careful not to break the vow.

A Spiritual Diary. When you go to bed every night you should review what you have done since morning. This diary may consist of questions you may ask yourself, e.g. “How many times have I forgotten God today?” “Did I get angry today?” etc.

With these methods, you can take to serious Sadhana, or practice of Yoga. And when your efforts are followed with earnestness of purpose, you shall achieve success in this very life.