Do whatever it suite you. They are yours.

Be careful if using glue. I had huge mess on my hands. The glue could end up on the stitched portion. I don't know how you could finish them off. Too bad that the pattern doesn't give directions. I've never stitched Christmas ornaments. If I were to finish them, I'd try to cut material a little larger than the ornament, flip and press a small seam allowance and then either attach the back to the ornament with a slip or blanket stitch. You could even place very thin batting in between the ornament and the backing. syagel is our quilter, she could tell you much better.

Hey, I have always used "Suede Cloth" to finish off the backs. You cut to the shape of the cross stitch and then use a overhand stitch to finish the edges together. I have also used felt...but...the finish of the suede cloth is so much nicer...in my opinion! :-) Hope this is helpful!!!!!! You can find the suede cloth at most Fabric Stores.
Merry Christmas and a Happy, Healthy 2015

There is a website called "The Twisted Stitcher" that you might want to look at. This woman, first name of Vonna, has a lot of tutorials on how to finish cross stitch projects. She has very clear pictures and well-written instructions. I have been finishing cross stitched ornaments for Christmas using her tutorials and have been pretty happy with the results. She does finishing for people and I have seen pictures of her work for Little House Needleworks. Worth looking into I think. Hope this helps.

Thanks, Sandy, I've never stitched ornaments but my granddaughter occasionally asks me to do one. I didn't know how to finish the back. I'll check the Twisted Stitcher out. I learn so much here. The suede cloth is another great idea.

On the cross stitch ornaments I made I ironed fusible fabric on the back of them to hide the stitches.