B.J. Fogg is the founder of Stanford University's Behavior Design Lab.
In his FBM [Fogg Behavior Model], behaviors are guided by motivation, ability, and triggers, and the reason we procrastinate is that we are having a problem with one or more of these. To build motivation, you need to have a compelling, emotional reason to do a task. To improve ability, you need to break a job into small, achievable steps. And to create a trigger, you should develop a set of cues that prompt you to act.
Here's a guide with more details on how to use FBM to stop procrastinating.