I am sure you have heard this a hundred times, but it really does work and I challenge you to do it just once this week. If you are not convinced it is the best thing ever, then you can stop doing it, but I will bet that you will keep at it because it works and makes things so much easier!
Next time you have a task you have been putting off or that is unpleasant or whatever, just plan to do it for 15 minutes and set a timer. At the end of that 15 minutes, you are DONE with that session. It is that easy. If you have a large tasks (like cleaning out a closet or the basement or whatever), a few of those 15 minute sessions will get it DONE. My biggest issue used to be that I thought I had to start and finish something in one session, so I would wait until I had several hours to do something (and who has that? Ever?) or there was a deadline looming (like you have to clear out the basement for a house showing – was that too personal?)
If you have a little more time, you can set the timer for 30 minutes, but any longer than that and it is not a timer-based thing. If you have more time than 30 minutes, then set your timer for 30 minutes and use the rest of the time for doing something fun for you all the while congratulating yourself for getting that much closer to finishing an unpleasant task.
So I have a new task and I know that I can do it in about 2 hours. Rather than wait for 2 hours to do it, I know that I can do it in 8 sessions of 15 minutes each. So if I do it every day, I know that in about a week, I can have it done, which is a great feeling, even before I have done anything!