I made an advent calendar this past week. I used a canvas and poked 24 holes in it and then used bobby pins for clips. I printed out 24 cards with family things on them.
They read things like: have friends over for hot cocoa and a fire; bake a treat; read a story; decorate tree etc
Here is a closer view of the bobby pins.
We have started it even though it is not December 1st because we are going away end of December, so We wanted to be able to go through all the days before we leave. This year we aren't getting a tree, so the decorate a tree wont work this year.