There are four categories for the development of sadhana:

1. Define your intention: Sadhana is the attainment of excellence and perfection in everything that is done. It begins with involvement in constant, continuous awareness and focus. In the absence of awareness and focus, sadhana is not sadhana; it is only a waste of time. There has to be awareness of the present mood and clarity of intention as to what is to be achieved. First of all, know your intention. That is the primary requirement of starting any sadhana. There needs to be an understanding of the aim. If the intention is not clear, the journey cannot be started. When the decision has been made, “This is where I want to go,” a path can be plotted on the map; this is the starting point for every aspirant.

2. Have conviction in the practice: The second point is the need for conviction in and dedication to your practice. One must believe that what is going to be practiced will lead to the goal. Conviction and practice must go together. If something is being practiced, one should believe, one should be convinced, one should know that the practice is going to lead to the goal; that becomes the focus, the aim .Every yoga and every practice has an aim, a goal, a target. Once the intention is clear and the path is plotted, the appropriate practices can be selected to achieve the goal.
3. Accept the change: The third aspect is accepting the change. If some change is experienced through sadhana, some transformation, be ready to accept it and not negate, deny or confront it. Many people do not accept change. They want to remain the same with an added quality, but how can one remain the same with an added quality? If a new quality is brought in, the reflection of that quality will be seen in one’s behaviour, one’s responses, one’s actions and one’s performance. There has to be openness to accept the change that occurs spontaneously and naturally, without compulsive and obsessive thinking as to why this is happening or why that is not happening. Accept the change in whatever way it is felt, in whatever way it is observed. It is your response to sadhana. When one eats or drinks, external things go into the body. Satisfaction, happiness and enjoyment is your response to what you are eating and drinking. In the same manner, accepting the change and allowing it to take place is your response, knowing that it is going to take you in a different direction where you will be different; perhaps better, perhaps expressive, but different to what you were before.
4. Practise continuous improvement: The fourth category of sadhana is improving the changed nature with more conviction, faith, determination and belief. Integrate the practice and the change into life, and improve on it.

This is the process of sadhana in four categories. It can happen at a sensory level, a mental level, an emotional level and a spiritual level. Asanas are practices to improve the quality and condition of the body and the senses. The method to improve the quality of the mind is meditation, in all its four aspects: pratyahara, dharana, dhyana and samadhi. In the same manner, just as meditation is the practice to cultivate the mental faculties and creativity, bhakti yoga is the practice to cultivate balanced emotions, and mantra is the practice to cultivate spiritual awareness.

Swami Niranjanananda Saraswati, Bhakti Yoga Book 6 , A guide to sadhana in daily life.