I was recently invited to answer the question in the heading. There were already 99 other answers, some of them very interesting. I tried reading all the answers, but gave up after the first two dozen or so. All that stuff about lists and apps and schedules and methods with trademarked-names might have been okay for some folks, but they didn't do much for me. I don't really use any of them, but I’ve been an incredibly productive person all my life.
I've published around a hundred widely acclaimed books, plus hundreds of articles. I've invented useful things and won a handful of awards for my writing. More than ten thousand people follow my tweets and my workshops are filled with people from all over the world. While doing all these things, I've also found the time and energy to support many volunteer causes.
My secret? I can do all these things because I apply just one principle:
Do what you love doing.
If you love it, you won’t need any of this tricks and tips. You might use some of them or make your own if they help you do what you love, but if you’re not doing what you love, no tricks will help much.
But, you say, "there are just some things I have to do, whether I love them or not." Well, first of all, re-examine those things and make a NOT-TO-DO list, to remind you to stop doing things you hate and don’t really have to do. And if there are still things left that you think you must do, experiment.
For instance, stop doing them for a few days or so and see if it matters. I remember when I had a job where we were supposed to put out a daily report for our manager’s manager’s manager. I started doing it every other day, and nothing happened. I switched to once a week, but again nothing happened. I cut down to once a month. Nothing.
After seven months, this senior manager finally came raging into my office demanding his daily report. I calmed him down and showed him what it had cost to do it daily when he only needed it maybe once a year. We negotiated a deal where on the day he needed it, I would drop everything and produce it in about two hours. That gave him what he needed and saved me two hours a day, 199 working days a year. Now, that’s productive.
But you may still have to accomplish a task that’s really needed, so your experiments don’t work. In that case, examine HOW you accomplish the task and use your imagination to find a way to do it that you really enjoy. For example, you can make a game of the task.
For instance, I once had a rather dull report I had to write regularly so I started each time by picking ten words at random from a large dictionary. Then I challenged myself to use all ten words somewhere in my report. Not only did this make the report into fun game, but I improved both my writing and my vocabulary. And, oh yes, people told me they enjoyed reading those reports, so maybe it made them more productive, tool.
If you enjoy doing a task, you won’t procrastinate, and you’ll do it with gusto. Voila! You’re now the most productive person around.
Not only does this principle work for you, but you can teach it to those who work with you, principally by example. When you do this, you're practicing a powerful form of leadership, helping all those other people be more productive. Think of it this way: It's the opposite of the dreaded micro-management. Instead of telling people how to do things your way, you're encouraging them to find their was to do things so they'll be a productive as you are.
(You think I’m making this all up? Well, how many people do you know who have accomplished what I’ve accomplished. You can check my website (www.geraldmweinberg.com) and then find some other people with a comparable history and ask them if they enjoy what they do, all day. I don't think you'll find many of them who spend their day making lists—unless they've made it into a list-making game.