Elder Nkiodim of Karoulia, a monk who lived on Mount Athos, gives us some simple instructions (this is an excerpt):
One starts prayer by standing and then, after introductory prayers, you can sit. The prayer is said in your mind and you use a prayer rope to help in your concentration. You move your fingers to the next knot on the prayer rope each time you complete the prayer. You hold your attention in your breast and not in your head or anywhere else. He says, "If you pray in your head you will have a head full of thoughts. You have to lower your attention." Its best to pray with your head lowered onto your chest.The key is to do what will help you maintain your concentration in prayer. He tells us that it is no longer prayer when you lose the sense that you are praying to God.
The elder says, "If he doesn't have the awareness that he's addressing the Lord, then he's only praying with his head. He knows that there is a God, and remembers that he is addressing God, but is not aware of it. But awareness leads a man to feeling. And when feeling comes, then he begins to weep. True repentance is then revealed. He becomes aware of his sins and begins to repent sincerely. He cries out to the Lord, "Forgive me, forgive me, have mercy on me!" Everything concludes in the heart." We pray without invoking any images.
The elder says, "Look upon the Lord and believe that the Lord is looking upon you. In spirit–pray in spirit!...We will our spirit pray to God the Spirit. Our spirit is united with God. When we turn with faith to God the Spirit, then the Lord will look upon us and the human spirit will be united with the Spirit of the Lord at the time of prayer." The main problem we face in prayer is attention.
The elder says, "Strive to maintain your attention in the words of the prayer. Then there is no place for thoughts to pop up, since attention is occupied with the words of the prayer.... When you pronounce the words be aware– as if you feel them."
The elder elaborates on this in another dialogue. He gives advice on how to eliminate distractions and maintain attention during prayer, "You should not enclose your mind in all the words at once, but in each word separately. You must do it like this: When you pronounce one word with your mind, you must at the same time listen with your mind to the word that is being uttered. Then, without a pause, immediately pronounce the next word the same way. Likewise with the third, fourth, and fifth words. Finish one prayer and then immediately without a pause, another, then a third, and so on through the whole prayer rope. Articulate with your mind the words of the first half of the prayer – "Lord Jesus Christ" – firmly and clearly. Pronounce the second half of the prayer – "have mercy on me" – close together, constraining your chest a little and restraining your breathing, but not too strongly, expressing in this way your contrition of heart and repentance. But this must be done calmly, so as not to irritate the nerves. At the same time you must constantly stand with your attention in your heart and look upon the invisible face of the Lord in His name. Pronouncing the words of the prayer this way, word after word, without pauses or stops, you give no place for extraneous ideas and thoughts to intrude. Laboring in this way with God's help you will see the fruit of your labour – the lessening of distraction."
We are advised to engage in this prayer for at least 30 minutes each day in a quiet place. Most Orthodox Christians have a special place in their home for prayer where they have icons, a cross, incense burner, a candle and their prayer books.
Yes, there are similarities in the practice of meditation and prayer, but there is much more to prayer. For a Christian, in the practice of the Jesus prayer, one will also gain benefits from the physical changes described in the meditation studies, but will gain benefits far beyond these physical ones. We must remember, our aim is not just longevity, happiness, or peace of mind, but eternal life with God in His kingdom. This is the aim of the Jesus prayer. Along with it also comes all the physical benefits ascribed to meditation.