Brian Tracy's book, Eat That Frog!: 21 Great Ways to Stop Procrastinating and Get More Done in Less Time
The sense of accomplishment can be addictive. When we finish a difficult task our brains release reward chemicals and produce a good feeling. Repeatedly tackling and completing these tasks can lead to positive reinforcement for these behaviors and it can become a positive addictive habit.
Some of the suggestions in his book are similar to those in his book No Excuses. This text focuses on specific strategies to tackle procrastination like using the Swiss cheese method or the small bite method.
I found his ABCDE method for prioritization to be helpful. E in this list stands for eliminate. I have used his early morning method to improve productivity. The cats often wake me up early in the morning and when I am unable to go back to sleep I use the time to complete tasks requiring focused concentration and minimal distraction.
The ABCDE method of prioritizing - 5 minutes