Procrastination is probably one of the biggest obstacles you will encounter in your life. It actively holds you back from all the things that you want to do, and the ironic thing about it is that it's entirely internal and easy to control.
1. Nobody Else Causes It
The first thing you need to know about procrastination is that nobody else causes it. You may avoid work because you feel sick or unmotivated, or because you want to deal with it another day, but those are all internal things that you can prevent to take back control of yourself and your life.
2. It's a Learned Habit
Procrastination is a learned habit. The more you procrastinate, the more it feels like an easy thing to do. If you've been putting off a report for two weeks, it's easy to put it off for another day, and another day, and before you know it you're out of time. The sooner that you stop the habit, the easier it will be.
3. Fear
It all boils down to fear. You could be fearful that you won't get the work done right, that it won't be appreciated, or that it will be hard to do. Of course, the more that you think that, the more the fear builds (see the point above) and the more you will be afraid to get the work done. To break your procrastination habit, you need to face your fear. Again, as in the first point, it's all internal. Nobody else causes your fear but yourself.