Personally, I'm a fan of getting out and doing things for others. We worked a Christmas Pantry one year, and that was awesome - handing out canned and packaged goods for families in need, and toys for the kids. Depending on where you are, there may be opportunities to volunteer as a couple or a family that could work for you.
For Christmas eve, we have a certain poem we read at midnight, and we watch a lot of cheesy Christmas cartoons - all the old-style ones like Rudolph and Frosty the Snowman and whatnot. For a while we watched Fantasia every Christmas eve, but we sort of fell out of the habit when we started just talking over it.
We haven't done a tree in years, though we always mean to; but our tradition has evolved to include a lot of ribbons and glitter, far less expensive than lights and foliage.