Nice idea! I remember in my first month or two of therapy, my therapist basically kept training me to list 3 things to be grateful for, and I was mostly annoyed about how much of the therapy was about that.
But, it turned out to be very effective, and being 'forced' to do my homework paid off. She later explained that she usually starts out with this 'exercise' because most of her clients are not just dealing with their particular issues, but also with those issues festering and affecting their sense of self-worth and day-to-day thinking process. And helping her clients improve in that area generally made it much easier and effective when dealing with the particulars.