Be honest; don’t lie. And say what you mean. This seems simple, but too many people have trouble with what are to me qualities that we shouldn’t have to strive for. I mean talk about a low bar: be honest and forthright. And be this way all the time to everyone you deal with. You want people to believe in you.
The alternative is being two faced and dishonest. Can anyone honestly say that is the reputation they want? I hope not, because reputation is everything. People remember.
If you do right by saying what you mean and being honest, people will know they can trust you. Trust and respect are the foundation for all meaningful relationships, whether professional or personal.
This is not something you want to take for granted. When the time comes for you to jump off a proverbial cliff, there will be more people there to catch you, i.e. help you get to where you want to go, if you are credible and trustworthy.