I used to be something of a procrastinator--and I can still be--but I've found that lists help me rein in this tendency tremendously. I'm by no means an expert of productivity, but I've learned a lot from experience and from reading what the experts on productivity have to say.
Why I Love Lists:
Lists Free Up Your Mind
I'm definitely one of those people who can lay awake for hours thinking about all the things I have to do tomorrow/this week/for the rest of my life and not sleeping. Then I wake up in the morning exhausted and can't remember any of the things I need to do.