The third habit builds on top of habit one and two. I keep iterating this message, primarily because I want to get better at it myself: you can be so much more effective if you focus on the important things instead of the urgent stuff that will undoubtedly cross your desk.
A lot of people will say things like “my main fault is a lack of discipline, I could never do X”. Covey states that he doesn’t believe this is true, but that the main problem lies with their priorities. They haven’t spent enough time figuring out what they think is really important.
A huge part in getting better at this is learning to ditch the unimportant things, and learn to say no to things that scream urgency but aren’t important for you to achieve your goals.
This is not something you tick off once and have under control. I need a daily check in with myself to evaluate if the things I’m doing are the absolute most important things to do. And still I get off track. It gets easier over time though: especially with a strong internal mission.