What I believe in: You are who you are
You are what you are, not what you do. This is about an identity that aligns with your values, what is important to you.
One overlooked tactic to maintaining good habits is saying you ARE that good habit, not that you must DO a good habit. For example: you want to get physically fit this year. Rather than saying, “I am going to run 5 times a week,” which is an extraordinary goal anyway, it would be better to say, “I am a fit and healthy person.”
When you identify with this person, your behaviour will align to it. When faced with the opportunity to have a sugary dessert or to sit on the sofa rather than go for that run, you should think, “But I am a healthy person. Therefore I will behave as a healthy person.”
What habits have you wanted to start and stick to that hasn’t worked previously? Who is that person you want to be, not what is the action you want to do?