Basically, what concentration is ability to defocus from all distractions except one object, thought or subject where focus is required. To acquire this ability, you can practice Trataka (presuming that you do not have any eye disorder), being aware of your breathe or yoga nidra that includes certain visualizations or chakra visualizations. But if you are with your mobile phone with continuously active internet connection that stimulates to keep continual presence on social media, etc, it will wander your mind. Install apps that helps you to monitor your usage of phone, else it will not be able to help you maintain your concentration. Gadgets are making us slave to them and distraction. Distraction is nothing other than destruction of our mind.
Trataka is gazing steadily at a particular point or object without winking of the eyes. There are various types of trataka. One of them is gazing on the candle flame which is placed three to four feet away at the height equal to your eye. In this trataka, you can sit straight, with relaxed body and look upon the flame with a steady gaze and without winking for one minute. After a minute, close the eyes, relax the eye muscles, and visualize the flame between the eyebrows for a minute. Then again gaze with open eyes on the flame for a while and then relax and close the eyes. Continue this for five to six minutes. Slowly increase the period of gazing from one to three minutes, spending equal time relaxing the eyes. This one is called central horizontal tratak. The other one is Bhrumadhya Drishti (Frontal Gazing) which is simply concentrating by directing and turning the half-closed eyes towards the space between the eyebrows. Another one is Nasagra Drishti (Nasal Gaze), wherein you have to gaze at the tip of the nose for one or two minutes. Word of Caution is that you should avoid too much strain on the eye muscles while practicing any of the above trataka. If you feel any pain or tiredness, close the eyes and relax the eyes muscles. Prolonged practice without the guidance of a qualified yoga practitioner may affect the eye muscles as well as the nervous system. In the beginning practise for a minute or two and gradually increase to ten minutes, but should without any strain. In this way, you develop your ability to visually defocus all other objects and focus only one object.
Another method of developing your concentration is moving your mind towards your breath observance. Feel the breath inside the nostrils during exhalation and inhalation. Feel their temperature - inhaled breath appear cool and exhale breath appear warm inside the nostrils. Or you focus on exhalation or focus on the gap between exhalation and inhalation or simply count the breath for a certain period of time.
Yoga nidra is relaxation technique that consists of concentrating chakras and certain visualizations which help you to develop concentration.
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