Concentrate on a Pure Soul YS I - 37

To steady and calm the mind, one can practice Pantanjali's Yoga Sutra I-37- VITA RAGA VISAYAM VA CITTAM- Or by concentrating on a great soul's mind which is totally freed from attachment to sense objects.

Here Swami Satchidananda states that a lot of people might not have much confidence in their own hearts. So a remedy to this is to think of someone with a noble heart, meditate on a heart that has given up attachment. Examples of these kind of people could be the Dalai Lama, Buddha, Jesus, Kabir, Rumi, Mother Teresa, Swami Muktananda, Swami Satchidananda, etc. So if you can't imagine your own heart being pure, dwell on someone's heart that has given up attachments to sense objects. Basically the main idea is to let the mind concentrate on something high and serene. or someone who has achieved this goal.