Sit down alone and in silence, lower your head, close your eyes, breathe calmly, and imagine yourself looking into the depths of your heart. Walk your thoughts through this into your heart and with the rhythm of your breathing say the Jesus Prayer (Lord Jesus Christ, have mercy on me). Say the Prayer moving gently your lips or better with your mind guiding it as we said into your heart, while at the same time try to push away from your mind all other thoughts. Progress patiently and calmly in this process repeating continuously the Prayer.
From the Filokalia writings of St. Symeon the New Theologian as used in the book The Way of the Pilgrim
Translated by Dr. Nick Stergiou