To control the mind the best and easiest method is to repeat constantly God's Name. Concentration is attained by fixing the attention on the sound of the Name. As the mind is concentrated, there must follow meditation upon the glorious attributes of God. Continuous practice of utterance of the Name and meditation stops the restlessness of the mind and merges it into the blissful, eternal and universal Self. God remembrance is not possible unless you have an intense longing to realize Him. This intense desire is called bbakti [devotion]. This longing must so seize your mind that you should feel a sensation of acute pain when you forget God on account of selfish desires. Your actions should also go to purify your mind, I.e., they should be done in a spirit of nisbkama [desirelessness]. Purity of mind means freedom from lust, wrath and greed. For a pure mind alone can see God. Concentration itself is purity. Forget not that the God that you seek is within yourself.

(Ramdas)