As previously mentioned, you can purchase a set of 12 Christmas ornaments that symbolize the Nativity. If you aren't interested in having an entire 12-piece Nativity ornament set, then you shop for some really cool individual Christmas ornaments that have a Nativity scene on them.
One such ornament would be a Nativity silhouette light Christmas ornament. This cool Nativity ornament isn't like your ordinary ornaments. Not only does this Christmas tree ornament have a silhouette of the Nativity on it, it also lights up when you put a small light in the back of it. This light can be one of your Christmas tree lights that are strung around your tree. You simply insert one of the single lights into the back of the ornament and you have a lighted Nativity silhouette.
Another cool Nativity Christmas tree ornament is actually a set of ornaments, but not your typical set that is put on a tree. This 9 piece glass ornament Nativity actually comes with its own gold foiled ornament stands in which you can hang the ornaments from. This saves you space on your tree and makes a really cool decoration anywhere in your home during Christmas. If you are worried about storing these glass ornaments without breaking them, these neat Nativity ornaments come in their own box for safekeeping. An ornament set like this will typically cost about $35.
One last really cool nativity Christmas ornament is a cross ornament that has a Nativity scene with Mary, Joseph and the baby Jesus inside of it. The angels celebrating above the Holy Family are just an added bonus. This $8 Christmas ornament is a cool way to display the Nativity on your Christmas tree.