Be constant in your practice, and one day the One who gave you the desire for the prayer of the heart will give you that prayer itself. When your heart's intention is fixed on God, it will keep lit the incense of your prayer, and wind of distraction will not put it out. do not worry about stray thoughts; they may come and go, but they will not take your attention away from God.
Advent is a season to ponder "all these things" in our hearts:
Thomas Merton calls us all to contemplation in his book of Contemplative Prayer ...
" ... the most important need in the world today is the inner truth nourished by the Spirit of contemplation -- the praise and love of God, the longing for the coming of Christ, the thirst for the manifestation of God's glory, truth and justice -- the Kingdom of God in the world."