Yea, and when you do not cry unto the Lord, let your hearts be full, drawn out in prayer unto him continually for your welfare, and also for the welfare of those who are around you.
--Alma 34:27
My heart being the figurative center of my thoughts and desires, it should be occupied with constant communion with God. When my heart is constantly filled by the Holy Spirit, I will be drawn instinctively to prayer, for the Spirit teaches me that I must pray always (see 2 Nephi 32:8).