Humility breeds a state of mind which evidences itself through action. There's not really more, except that actual humility isn't something you can measure directly. So the advice "be more humble" isn't actionable. "Work to pay back the debt you owe" is.

Humility like arrogance are both wrong. Humility is unearned guilt, unearned self-doubt, and arrogance is unearned confidence, unearned pride. It's best to have a sober assessment of one self and act accordingly.