You should aim to practise this technique for at least half an hour every day without fail, until you can practise it easily without effort.
Awareness Mindfulness during ajapa is essential. You must be mindful of every activity, whether breathing, mantra or thoughts. Without this mindfulness you will slip into the state of drowsiness. This called tandra or laya in Sanskrit. It is a great obstacle that has to be overcome. It is the stumbling block, the greatest impediment, the greatest hazard that faces every person who tries to practise meditational techniques. How many times have you practised a meditative technique and found that your mind has been brooding over some problem for many minutes without your awareness? During this period you were completely lost in your thoughts. It is only after the period of brooding that you realize you were brooding. This is in total opposition to the path of meditation. You must be aware of what you are doing. You must be awake. If you feel sleepy, go and take a cold bath or wash your face. Or practise a few rounds of surya namaskara. Without developing mindfulness you will never be successful in meditative practices. The mind can wander from the practice in hand . . . there is nothing wrong with this. In fact, initially this is positive, for it helps to release pent-up mental problems. But you must be aware of the thoughts as they arise. You must know that you are thinking about a certain subject. The mind will always wander here and there; it is its very nature. Let it but maintain mindfulness. In ajapa you must be alert to all things that occur in the mind and the processes which are part of the practice. Don’t suppress thoughts; this is not the way to harmonize the mind. Let them arise, but while simultaneously being attentive to the breath and mantra movement of ajapa.
General note We have described the five stages of ajapa in order to prepare you for kriya yoga. Ajapa is a powerful technique, especially if it is done continuously throughout the day and night. Many great yogis have attained highest stages of consciousness through this method alone. We realize that continuous practice is difficult for most people, especially those who have many responsibilities and this is nearly Jill of us. But at least try to do ajapa as much as possible, whenever you find the time. Instead of brooding over past regrets and future problems, do ajapa. You can practise at any time . . . before sleep, before lunch, while on the bus or train to work or wherever. This will help to harmonize the mind and allow the deeper mental impressions (samskaras) to arise to conscious perception. This is the way to equanimity in life.