Continual prayer and constant remembering. Practicing silence and approaching stillness. These are the loves and labors that lead to the indwelling of the Lord. Once you feel the warmth, don't stop. Once you see the inner glow of your heart, don't stop. Keep going and God will set you aflame.
"Apply the following comparison to this: When a spark falls on a hot object, the object begins smoldering gradually; then it catches first until finally it is engulfed by flame, and, being dark by its essence, it becomes bright and shining on account of the fire that engulfs it. That is how it will be for you. Growing warm gradually, you will begin to glow; the spiritual flame will break out, and, once it has penetrated to all parts of you, will engulf you and make you bright, although you are in and of yourself dark."
- St. Theophan the Recluse. "Letter 52." The Spiritual Life and How to be Attuned to It, translated from the Russian by Alexandra Dockham, (Arizona: The Holy Monastery of St. Paisius, 2017), p. 211-212.