Decide that you are only going to work on it for five minutes. Doesn't matter what you have to do just tell yourself "five minutes and I'm done". You will often find that after you get started on a task, even knowing you will only be at it a short time, that you build a momentum that propels you forward. Then when you are done with five minutes or the whole task reward yourself. It can be something small like 10-15 minutes on snapzu or another cup of coffee.
Decide that you are only going to work on it for five minutes. Doesn't matter what you have to do just tell yourself "five minutes and I'm done". You will often find that after you get started on a task, even knowing you will only be at it a short time, that you build a momentum that propels you forward. Then when you are done with five minutes or the whole task reward yourself. It can be something small like 10-15 minutes on snapzu or another cup of coffee.