"Advent Calendar Activities"

Hi Friends! I have this little Advent Calendar that has the 25 doors that open up. Instead of putting candy or a little gift in there, I had the idea of putting an activity in there. Each morning, I'd like to have my boys open up the door, and then have there be an activity in there that they would have the whole day to complete. My kids are young, and I plan on changing the activities to more "service" type activities when they get older, but for now, I am open to any and all suggestions. I need to come up with 25 of them! A few examples I have include: "You need to tell each member of the family 3 things you appreciate about them" or "List 3 things you are thankful for" or "Go to a church or school's Angel Tree and choose a name off the tree, and then go buy (parents will buy- and then maybe as the kids get older have them spend $10-$20 of their own money) a present for a less fortunate or disadvantaged child.

So Friends, if you have any ideas, I'd greatly appreciate you posting your ideas here, and together, hopefully we can acquire a nice list of 25 activities. Thank you!