The purpose of yoga is to withdraw our mind from external objects and to focus the mind within. There are certain simple methods by which, this can be practiced. In order to effectively practice this, haṭhayoga prescribes eight different practices, which is popularly known as aṣṭāṅga yoga. In order to achieve quick results, we have to follow these eight steps in a simplified way.
First is yama which is nothing but self-control. We have to be good to others and in order to be good to others, we have to shed our ego. We have to live a highly disciplined life. This does not mean that we cannot enjoy the pleasures of material life. We should not shirk our responsibilities towards our family. Karma yoga is very important, if we want to lead a disciplined life.
Second is niyama which is evolution of yama. Shedding anger, short temper, speaking softly with care, compassion and love, avoiding gossips, talking behind someone’s back are the important things to be controlled here. Apart from this, adequate care should be taken in the food we take. Food should not be spicy and should be with less salt. Lot of fruits and milk related products should be taken. One should not sleep for long hours. Most importantly, when one wants to reach the pinnacle of spiritual practices, he or she should stay away from crowd. In remaining alone, will make us to look within without distractions.
Third one is āsana. The most important thing in any sitting posture is keeping the spine erect. This does not apply to meditative postures alone. Whenever one sits, spine should be kept erect. Those who are not able to practice various types of āsana-s as prescribed in Haṭhayoga Pradīpaka can perform simple stretching exercises such as hip twisting and forward-backward bending. Jogging and skipping are other good exercises.
Fourth is prāṇāyama. Yogic breathing (abdominal breathing) and nāḍi śodhana prāṇāyāma are the two important breathing practices to be followed without fail. After mastering these two, we have to learn to slow down our breathing rate to calm down our mind.
Fifth one is pratyāhāra, which means withdrawal of senses from external objects. When we are doing mantra japa, this can be practiced with ease. This is explained in this article : HOW TO PRACTICE MANTRA JAPA
Sixth one is dhāraṇa which is fixing our mind. The above article also explains how to do dhāraṇa. At the end of dhāraṇa, we will forget the existence of our body.
Seventh one is dhyāna or meditation. If all the above six are practiced perfectly, there will be no difficulty in meditation. Following article explains meditation : MEDITATION TO ATTAIN DIVINE GRACE
The last one is samādhi, absorption into Divine Consciousness. Samādhi can be reached only if all the above are practiced. Different stages of samādhi-s are explained in this series: GURUJI SPEAKS
Conclusion: Simple life devoid of ego is the basic requirement for spiritual life. One should be with only one mantra and one Devata, if his or her aim is Self-realization. Too many mantras and too many Devata-s will confuse the mind.