Is is easier for you to get motivated to accomplish a task if there is a reward waiting for you at the end? Rewards can be very helpful motivators, though if seeking a reward becomes your main motivation in all circumstances, then your self-interest will get in the way of core motivations like compassion and generosity. When more selfless emotions guide you, you will reward yourself and the peoplw your actions touch far beyond your expectations.
However, setting up a small reward system to help motivate yourself can be positive and useful. For this exercise, identify one or two tasks that you've found it difficult to accomplish...things that you perhaps do not feel passionate about which you still need to do...and set up a reward system. Divide the task into pieces, and give yourself something to look forward to after you complete each piece. Rewards might include taking yourself to the movies or going out for a special dinner.
When you finish the task, notice how well the rewards worked. Did they make a difference? What other, nonmaterial rewards could you replace them with? Dig deep and find out what your core motivations are. What does your choice of rewards say about them?