Aretē is excellence at your purpose. A knife's aretē is cutting. Yours is your craft, done well.
Aretē meant excellence of any kind: a knife's aretē is cutting well, a runner's is speed, a person's is living well. Homer tied it to noble birth; Aristotle saw it as a habit you build.
A pitmaster who has smoked brisket every weekend for 30 years has aretē.
Aretē for a manager: everyone leaves a one-on-one knowing their next step.
Practice it in Skepsis