Rubrics (literally red letter words) are often ignored, argued with, and intentionally broken but I think it is foolish to think that we can be found faithful in the great things of the Kingdom while playing fast and loose with the little things of God. In fact, I have often found that those who are unfaithful in those little things are also unfaithful in the big things. In this, our Lord finds the same connection.
Whoever can be trusted with very little can also be trusted with much, and whoever is dishonest with very little will also be dishonest with much (Luke 16:10). This wisdom was also noted by St. Augustine. Quod minimum, minimum est, Sed in minimo fidelem esse, magnum est. [What is a little thing, is (just) a little thing. But to be faithful in a little thing is a great thing.]
(from St. Augustine’s De Doctrina Christiana, IV, 35)
On several occasions questions have arisen in winkels (local gatherings of clergy) in which what we believe has been questioned and I have asked "what do the rubrics tell us to do?" For in the rubrics we see doctrine in practice. You can laugh about those little red letter directions in the hymnal, missal, and agenda but you dare not take them lightly. They were placed there for a purpose by people who understood (even when we forget) the connection between belief and practice that has been the core and center of our church's life since the beginning.
Little things matter. As a parent, we often presume that it is the big stuff that tests our mettle but in reality the parent's most profound tests come in faithfulness in the little stuff. As one example, teaching the doctrine of prayer is less significant than giving the great witness of parents praying, of praying with their children regularly, and praying at times of special need. I would say the same thing applies to pastoral ministry. We face our greatest challenges not in the once in a decade issues that confront us but in the daily prayer, teaching, preaching, presiding, visiting, counseling, and such. Little things count and the Lord does not ignore those little things. Jesus was not a big picture guy and neither should we be. We must be both and the little things will matter even when we do not see it.