Brian Tracy on prioritizing and sticking with that priority until you have completed it:
The ability to start and complete your most important task determines your productivity more than any other skill. Maximum performance is possible only when you concentrate single-mindedly on the task—the most important task, and you stay at it until it is 100 percent complete.
Do the Most Important Task
You cannot do everything, but you can do one thing, the most important thing, and you can do it now. By setting goals and priorities, and then by selecting your most important task, you can dramatically increase your level of productivity and output.
Single handling is perhaps the most powerful of all time management techniques. It can increase your output by as much as 500 percent. It can reduce the amount of time you spend on a task by fully 80 percent—by the very act of launching into the task and disciplining yourself to stay with it until it is complete.
Refuse to Stop till Done
Picking up a task, putting it down and coming back to it several times, dramatically increases the amount of time necessary to complete the task. On the other hand, picking up the task and refusing to put it down until it is done enables you to accomplish vastly more in a shorter period of time than you thought possible. By disciplining yourself to concentrate single-mindedly on the most important thing you could possibly be doing, and then by completing that task, you increase the quantity, quality, and value of your output substantially.
Feel like a Winner
You can have all the talent and skill in the world. But if you cannot discipline yourself single-mindedly to complete your most important task, you will always have to work for someone else. You will always have to be supervised by someone who can make sure that you do what you should do, when you should do it. The good news is that every time you complete a major task, you experience a surge of energy, enthusiasm, and self-esteem. You feel terrific about yourself. You feel happy and elated. You feel like a winner.
By assigning yourself a large task and then by disciplining yourself to concentrate single-mindedly until the task is complete, you eventually develop the all-important habit of task completion. You program your subconscious mind in such a way that you look forward to major tasks because you know how good you are going to feel when you have completed them.
Resolve today to develop the lifelong habit of task completion. You do this by selecting your most important task, getting yourself organized, and then working on it wholeheartedly until it is complete. Do this over and over until this habit of single handling is firmly entrenched.