Are you thinking about Christmas yet?
1. Cut out pictures of doors and windows from magazines/catalog. (I used the Pottery Barn Christmas catalog.)
2. Mount the pictures on card stock, cut them out, tape them onto a poster board.
3. Add your countdown numbers to each picture.
4. Tape a little note under each door or window. For my family it's things like: make a treat, read Christmas stories, go on a family outing, invite a friend to play, movie or game night, family or church parties, etc.