A number of my clients are so perfectionistic that they make every task painful to complete. So, they procrastinate until they must get it done, when usually it's, ironically, too late to do a good job.
I suggest that for every major task, they set a timer for 3 minutes and, in that time, list all the steps needed to complete the task. Then tackle each step sloppily, perhaps in just three minutes each. Then keep revising each step until it's done well enough.
So, for example, today alone, I used a variation of that technique with two clients:
An epidemiologist at one of the nation's most prestigious universities had been procrastinating writing a megaproposal. I said, "You have three minutes to list all the steps to getting that proposal done." After the three minutes, he had a complete list of bite-size tasks and said he now feels more motivated to get the proposal done.
An architect has trouble creating designs in a timely manner. Indeed, the longer his deadline the more trouble he has getting it done. We set a timer for 3 minutes and I said, "Draw the most brilliant design for that home addition that you can sketch in 3 minutes." He said that his three-minute design was better and less painful to create than if he had taken a month.