The repetition of mantras
by Atman Nityananda
Repetition of mantras, either mentally or aloud, is the best way to change the structure and vibration of the mind.
It also diminishes the egoic tendencies, emotions, desires and impulses.
With this comes peace, stability, clarity and joy!
Read about mantra practice here:
Mantra Yoga Sadhana By Swami Sivananda