Do not spoil yourself. From time to time, hold back a reward. "Hold back a Reward, Escalate a Goal"
If you are a procrastinator try this: Hold back something you enjoy. I personally like viewing Facebook from time to time, especially when I have other things to do. It had the potential to feed my procrastination better than any other. These days I use this to motivate me to finish something of far greater importance to my agenda. You may think about food; Tell yourself: "Once I finish this, I'll go to this restaurant and get that ice cream sundae I always love." But, instead of doing whatever you feel like doing, withhold some things, I promise you, they will taste sweeter once you finish the job you were meant to do.
Have a great day!