A study published in the October 2011 issue of the Personality and Social Psychology Bulletin supports a key Ridiculously Efficient tenet: create urgency to incentivize productivity.
In the study, researchers asked women to list a tempting but unhealthy snack. Half of the women were told to remember that if they saw their tempting food, they wouldn't break their diet; the other half weren't given this "implementation intention." The women who successfully connected their goal and their temptation were less likely to give in to their temptation.
It's simple to relate this to productivity. Recognize your temptation (checking Facebook, trolling on Reddit, chatting with a coworker) and think about the situations in which you're most likely to encounter that temptation. Then work out a plan to fight that temptation and achieve your goal (quit your browser or close all windows until you finish that project). Because you've already given yourself tools to fight your temptation, you're less likely to fall prey to it.