Procrastination can be a serious problem leading to job loss, high anxiety and even significant psychological disability and dysfunction (according to wikipedia). To avoid excessive procrastination, most researchers grow a sense of professional urgency.
Most people rely on extrinsic pressures. In Computer Science—for example—we often organize our work around a few conferences with fixed submission deadlines. Others will compete with fellow researchers for funding or a specific research goal.
I prefer intrinsic motivation. I avoid fixed deadlines and competition. I choose problems that I want to solve, for myself. In this intrinsic mode, you find that you cannot get yourself to work on some problems. For example, you ran some experiments or derived some results, but you cannot begin or finish writing the paper. After all, there is no deadline, no competitor to beat, so why bother if you do not feel the urge? In some instances, you are merely lazy. But what happens if you make good progress in other, similar projects? Simply put, procrastination becomes an indicator for uninteresting problems.
Whenever I procrastinate too much, I start to question the importance of the work. Often, I find that it is better to drop the work entirely.