In the old days, work was self-evident. Fields were to be plowed, machines tooled, boxes packed, cows milked, crates moved. You knew what work had to be done--you could see it. It was clear when the work was finished, or not finished. Increasing your productivity was all about making the work process more efficient, or simply working harder or longer.
Now, for many of us, there are no edges to most of our projects. Most people that I know have at least half a dozen things they're trying to achieve or situations they'd like to improve right now, and even if they had the rest of their lives to try, they wouldn't be able to finish them to perfection. You're probably faced with the same dilemma.