a habit
Examples
Quality is not an act, it is a habit.
Liberty is not merely a privilege to be conferred; it is a habit to be acquired.
Make a habit of two things: to help; or at least to do no harm.
A habit is first a wanderer, then a guest, and finally the boss.
When a habit begins to cost money, it's called a hobby.
If you make a habit of buying things you do not need, you will soon be selling things you do.