Man's task is to control his action in the direction of good so that he may grow from time to eternity, from the smallness of himself to the greatness of God. The means of this control, right reason and good will, are within the power of every man. They are not the privileges of rich or poor, of the powerful or of the weak of this present world. By using the reason and the will properly every man can direct his steps unerringly forward to the vision of God in which his true happiness is to be found.
-- My Way of Life: Pocket edition of St. Thomas; the Summa Simplified for Everyone. p. 186.
This reminds me of Aristotle's advice to cultivate our virtues (or skills) and to moderate our actions through thoughtfulness, as a means to find eudaimonia. But of course when reflecting upon Aquinas it is always appropriate to remain mindful of Aristotle.
If this sort of Highbrow advice is to your taste, please click HERE.