You have this report to write, or presentation to prepare, or project plan to put into place. It is daunting. Too many parts to it. Too many issues to think about. You find yourself deferring it and feeling a little anxious when you think about it. It is just too big of an undertaking, and/or a sign of procrastination, and/or a sign of wanting it to be nothing less than perfect . You end up delaying it until there is no room for delaying any further. Then it becomes a high pressure situation. In addition, work quality suffers. If other urgent demands come up at the same time, and they will, then you've got one of these "situations" on hand.
The power of working in iterations and helping better manage such a project or task could involve the following:
Give yourself permission to spend, let us say 40 minutes, to do a brain dump relating to the project or task (let us call it project for now). Remind yourself that this is just a brain dump and not go into analysis or conclusions yet. Capture related issues, ideas, worries, whatever else comes to your mind. Don't worry about organizing or ordering yet. Include a list of potential resources that you may have access to or would like to have access to. Be creative! Be bold! Dare to put down freely what comes to your mind!
Leave the above alone for a bit. This may be an hour or two, or a day or two, depending on the magnitude of this project. This will allow the mind to absorb the information and do its own background work on it. It may be quite beneficial to engage in some creative work or physical exercise type activities during this time.
Take another stab at it. This can also be yet another 40 minute session. In this iteration, you may add additional thoughts, and your mind may have already come up with new and interesting ideas on how to approach the project. Capture them and then move into organizing your thoughts and get them ready to take action. This probably means breaking down what needs to get done into manageable components that you can then schedule on your calendar, and/or delegate to others.
Now that you have a plan, start execution according to plan. If possible and applicable, involve others. Setup a dry run or a review session with the people who could provide meaningful input, and who might have some stake in the success of this project. Create a deadline that can help you focus your energy and motivate you to get things moving.
Give yourself time to refine, gather more input, and go for the final victory.
Of course customize the above as you see fit. Don't forget to stop and celebrate victory against procrastination and perfectionism, before you start the next project or task!