This year we made a *thankful tree*. This is the first time for us to make one, but I've been seeing so many around the blogosphere and it seemed like a great project for the kiddos. And they are enjoying it!
We simply found a branch in our backyard, stripped the leaves off of it, stuck it in a block of foam and put it in our fireplace ash bucket with a little bit of moss hiding the foam--then started adding our own paper leaves that have things we are thankful for written on them. Very easy! I just used some leaf cookie cutters for stencils to draw the leaves, but I'm sure you could find a template online or free-hand some leaves, too.