Humility is a special Virtue that is independent of the three Principles. It’s about being aware of your place, part of the big picture which is all of life and existence. It is to remind us that our accomplishments are just accomplishments. They are not a means to glory or recognition. While we are certainly allowed to earn a living and do things for ourselves, our actions should be taken with the knowledge of how they affect others. We do not choose to profit at the cost of harming anyone.
Every decision we make can have multiple solutions. Usually there will be several different responses that could all be considered to be along the path of different virtues. Through Humility, we consider which choice would be for the greater good overall.
Live a humble life, do not boast or draw attention to yourself. Be content that your works are a boon rather than a burden. Allow all of the Virtues to guide you.