(Some of these things could be done for other holidays too!)
Our Christmas Card: I designed it in MS Word with the fantastic Budmojiggler font (download at dafont.com) with fun little flourishes from dafont too.
B&W Abstracts for the Tree: H and I painted with black acrylic paint on a large sheet of parchment paper. I then cut it into smaller rectangles. The frames are made from cereal boxes, painted with black and gold acrylic. I just taped the paintings to the back of the frames and tucked them into the tree. I love the way the light shines through the paper!
Christmas CardDisplay: Tack ribbon to the top of a door or window and secure cards with tiny clothespins. Last year I decked the kitchen with yarn and attached the cards all around the island. I also attached cards to what was the "Bat Tree" then became the "Fall Tree" and is now the "Christmas Card Tree." (I think I'll take it down after NYE and figure out a new display for that table.