I found making a small deal with yourself to be quite effective for me. Here´s how you do it:
Promise yourself that you’ll work on something for just 5 minutes. After those 5 minutes you can do something else if you want to. But make a note on your schedule when you will come back to the task and work another 5 minutes with it. Not matter how unpleasant a task may be, you can often talk yourself into working 5 minutes on it.
I’ve found this one to be effective to make a dent in those tasks you have put of for a longer while. After you’re done with those first 5 minutes the next 5 minutes will feel a little easier. And after that the next 5 minutes will feel even easier. Or maybe you raise the bar to 10 minutes of work. Getting some actual work done on that task, if only for 5 minutes, gives you a rush of exhilaration. Making a game out of how much work you can get done in those 5 minutes can also be a small but in its own way fun challenge.
It´s was a part of my article on procrastination
7 ways to move beyond procrastination