What are some of the most effective habits or strategies mentioned in the article that can help someone transition from being a good manager to a great one, and why are they so impactful?

Clear expectations and constructive feedback are key to effective management. A good manager focuses on solutions, not just pointing out problems. I suggest to read a full information about How to Be a Good Manager article - https://makeheadway.com/blog/how-to-be-a-good-manager/ and you will be surprised.