A popular devotion within Eastern Christianity is the Jesus Prayer (Prayer of the heart or Prayer of a single thought).
The origins of the Jesus prayer are thought to come out of the hermitic tradition of the early Desert Fathers who settled the Egyptian desert in the 5th century. The prayer also has scriptural roots reflecting the lesson taught in the parable of the Publican and the Pharisee (Luke 18: 10-14). In the parable the Pharisee demonstrates the wrong way to pray: “Oh God, I give thee thanks that I am not as the rest of men, extortioners, unjust, adulterers, as also is this publican.” While the publican prays correctly and in humility: “Lord have mercy on me, a sinner.”
In the eastern tradition the prayer is said or prayed repeatedly, often with the aid of a prayer rope.
Monastics have long sessions of praying the prayer hundreds of times under the guidance of an elder. The ultimate goal is to “internalize” the prayer so that one is praying unceasingly as St. Paul urged the Thessalonians to “pray without ceasing” (1 Thessalonians 5:17).
I find that this prayer, although very simple, puts us in a right relationship with God and can open our heart to receive guidance from the Holy Spirit.
You can also make your own prayer rope. Some use the exercise of tying the rope as a tool for prayer. Here is a video about how to make your own prayer rope.