I don't have it licked yet, but I think I've identified some of the things that will help.
1. The more you do of something, the more interested you become in doing it. The less you do of it, the less interested you are in doing it.
2. Action precedes intention. Rather than waiting until the circumstances are perfect and you feel like it, do some of it and the feelings will come along.
3. Break it into bite-sized chunks. Usually our avoidance is caused by the emotional feelings of being overwhelmed which our brain is trying to protect us from encountering. This may be because we tend to be too perfectionistic, we are missing some piece of information that we need for how to go at it, we have had a bad experience with it in the past and are afraid of failing, or the task just seems too big. By looking at it just a little at a time, our brain gets the message that we will be okay - just around the time panic sets in we are done that little bit that we set for ourselves to look at. This may be very small - asking a question to one person. Looking up one website. Sorting out the stuff that you will need. Going to the store for the materials needed to accomplish the task, etc.
4. Misery loves company. We tend to be very influenced by the actions of those around us. Finding someone to work alongside you at a task they are avoiding will encourage both of you to do better. Similarly, hanging around someone who is also procrastinating prolongs the problem.
5. Try to chart a map of the steps from where you are to where you need to be. This makes it seem more approachable and like you are in charge of it, instead of it being in charge of you.
6. Accountability - build in some mini deadlines for yourself and preferably a times along the way when someone else actually sees where you are at. Most of us work best under pressure.
7. Actually schedule regular time in which to work on it, rather than leaving the time to work on it up to chance. Little short spurts scheduled more often are easier to face than one long spurt at a time when you feel like it. I've done this with exercise and with cleaning by setting my watch on the hour and doing X amount of squats or picking up 10 items and finding homes for them etc.
8. Try to identify the fear/emotional issue that is keeping you from wanting to face what is in front of you. When you deal with the source, rather than the symptoms, it is easier to overcome.
9. Sometimes completing something is more important than having it exactly as you visualized it and never ending up getting it done.
10. Try to deal with anything within your power right away. This is particularly true for things like phone calls and emails. It's easy to forget, feel less urgent, or procrastinate returning communication the longer you put it off.
11. Recognize that the longer you avoid something, the bigger it becomes in your head. By facing it, you shrink it back down to its actual size, rather than what it has become in your mind.
12. Develop routines for yourself. Little children do not put up as much fuss about doing things when they get into the habit of doing them every day and it is not a surprise. It becomes a habit and they are also emotionally prepared for it. We aren't so different, even when we have the autonomy to choose when we want to tackle something.