Mana needs to be maintained through the active practice of tikanga. Mana is not a theoretical concept, but a living, vibrant part of the Traditional Maori world.
Through words, followed up by actions, mana is maintained and enhanced. The traditional Maori world is based on oral traditions, hence the importance of being honest, and having integrity.
If you say you are going to do something and then do it, your mana is enhanced as people get to know that you are honest, reliable and trustworthy.
By saying you are going to do something, then not do it, you soon develop a reputation for being a liar, unreliable and not trustworthy. Because you also have your birth mana, is this a reflection of your ancestors or your tupuna?