1 general:: Phrase(s): make a practice of something [and] make something a practice to turn something into a habitual activity. • Jane makes a practice of planting daisies every summer. • Her mother also made it a practice.
McGrawhill's American Idioms And Phrasal Verbs
2 general:: Habitually do something, as in Bill makes a practice of checking the oil and gas before every long trip. [c. 1900]
American Heritage Idioms