A couple of weeks ago I shared the activity advent calendar we did last year. This year I made one on a bit of a smaller scale. I made up an envelope advent book. Each "page" is an envelope that has the # of days until Christmas on it and inside each envelope is a card with an activity for that day.
The post from last month has a list of activities and I can add the card in each night depending on how our schedules change for the next day. If I decided to get them a small gift instead I put a clue as to where it's hidden or one day just told them that a secret prize would show up at some point during the day and to keep their eye out.
This is my boys' favorite activity of the season. They love the intentional time spent with them.