What a lovely idea! I had never heard of them, don't know if that's an American thing or not. Lots of other Americans in this game seem to know what they are. Anyway, I'll add to it.
Things you might place in the window of a home made Advent calendar
1. Chocolate
2. Perfume
3. Earrings
4. Sprig of mistletoe
5. Small gift box
6. Ring (one of 5 gold)
7. Glitter Pens
8. Lottery ticket
9. A drawing
10. A lucky charm
11. Two tickets to a concert you know the person would love to go to.
12.