Take heed therefore unto yourselves, and to all the flock, over the which the Holy Ghost hath made you overseers, to feed the church of God, which he hath purchased with his own blood. (Acts 20.28)
One particular generally-neglected spiritual service in our day is that of family visitation. If not neglected, it is often caricatured, but the Biblical duty of undershepherds, pastors and ruling elders, to provide spiritual oversight, encouragement and admonition to the flock under their care.
Derrick J. Vander Meulen, "Shepherding the Flock Through Family Visitation," in Called to Serve: Essays For Elders and Deacons, p. 214:
Put simply, family visitation is the practice of elders and ministers officially and regularly visiting the members of the congregation in their homes.
John S. Watkins, A Hand-Book For Ruling Elders, p. 30:
It is the duty of the elder to visit the members of his church. It is impossible for him to take proper oversight over them, look after their spiritual interests, and give them due attention, without coming in personal contact with them in their homes.
David Dickson (1821-1885) writes in The Elder and His Work, p. 45:
If the great ends of our office are, by God's blessing, to be attained, it is plain, in the first place, that the elder must know the people in his district. He must be acquainted with them all, old and young, their history, their occupations, their habits, their ways of thinking. They and their children should be his personal friends, so that they naturally turn to him as to one on whom they can depend as a kind and sympathizing friend and a faithful counselor. He must know them as they are at home, at their own fireside. As Dr. [Thomas] Chalmers said, "The way into a man's heart is in at the door of his house." And he must keep up this knowledge by visiting them from time to time.
The practice, rooted in the "house to house" ministry of Paul (Acts 20.20), is articulated officially in the 1618-1619 Church Order of the Synod of Dordt:
The office of the Elders, in addition to what was said in Article 16 to be their duty in common with the Ministers of the Word, is to take heed that the Ministers, together with their other Fellow-helpers and the Deacons, faithfully discharge their office; - and, insofar as circumstances of time and place permit, to do house visitation both before and after the Lord's Supper for the edification of the congregation, in order particularly to comfort and instruct the members of the congregation, and also to exhort others in respect to the Christian Religion.
Peter De Jong (1915-2005) wrote a book designed to encourage both undershepherds as well as parishioners in this edifying spiritual exercise: Taking Heed to the Flock: A Study of the Principles and Practice of Family Visitation. I have found it to be very helpful personally and I commend it highly to those interested in better understanding what it means to shepherd the flock of Christ.