Big Little Sister says, "I didn't practice my guitar yesterday."
Knowing that she had, more likely than not, already decided a solution for herself, I simply quipped with a big I'm-joking-smile, "Well, I guess you'll have to practice twice today."
To which she replied, "I decided that I'm not playing Harry Potter (a computer game) today, because that's what I did yesterday, and why I didn't practice."
She made a bunch of signs. They say things like "guitar, read, blog", activities that she would like to accomplish today. She had her sisters hang them around the house, and so when she sees one of them, it will be a reminder for her to accomplish that activity. I guess, in her way, it's her "to do" list.
What a good idea!