Between the two of them, there are so many feedings, diaper changes and naps that I know it would be extremely difficult to try to remember the details for the parents. Some days I need a checklist for feeding the dog since I can't remember!
Whenever I care for infants, I make a habit of writing down their schedule for that day. It's always helpful to mothers to have that to take home and refer to if they wonder about something later that evening.
With two so young, I knew I'd need a more efficient method than just a scrap of paper. So we made up a simple document and I hung a clipboard on the kitchen wall for each child.
So far this has worked great!