All of us could probably do with a more productive workflow. suggests applying Parkinson's Law to our daily routine:

Parkinson's Law states that "work will fill the time available for its completion." This is a side effect of focusing on doing work instead of getting projects completed. Give yourself strict deadlines and cultivate a desire to finish projects, not just check tasks off on a to-do list.
You could do this by setting a timer for a set amount of time to finish a project— once the timer sounds, you are done and must move on to something else; a similar method is working in 48 minute increments.