First principle: Schedule work blocks (not just meetings or appointments) and then honor those commitments when they appear on your calendar. It’s easy to keep an appointment with other people, especially if they show up in your office at an agreed-upon time. It’s much more difficult to keep an appointment with yourself wherein, say, you’ve set aside time to read something important or write something or synthesize your notes from a meeting.
If you become an expert at applying the above principle, you will become more productive because, as you develop certain goals or aspirations, you will immediately schedule the work blocks it will take to complete them or reach them. And then, when you keep those appointments, the work will add up, the work will get done.
Additionally, you will become a more effective collaborator, in part because, when someone asks you to do something, you will be able to quickly tell him/her: “I’ll handle ______ on _______.” Communicating about the scheduled work will help to settle your partner, allowing him or her to move on to other tasks. And actually delivering on your promise to complete said work at said time, again and again, will build the kind of trust that allows collaborative work to flourish.