I was a terrible liar, I started by being honest in therapy first, got rid of all the secrets, then I made a commitment that if I lied I would go back and tell the truth; mostly to the person I had lied to, if that was difficult I talked about it in therapy. Part of it for me was the lying from an abusive childhood and not being believed about the abuse, having to cover the truth about my family. It was also a self-esteem issue; I did not want anyone to see me as I really was so I would lie to make myself look better/more interesting. It was not actually a hard habit to break once I faced up to it. I think any habit that is deeply ingrained won’t just stop but it was for me one of the easiest things to change.