The other day I made a comment about knit or otherwise crafted ornaments being far superior to those plain glass balls you can buy at any store this time of year. But the truth is we probably all have some of those balls hanging on our trees, don't we?
If you want to jazz up a plain glass ornament, knit it a cover. I love this Cat's Eye Lace Ornament, which can be worked up in not too much time and makes a lackluster ornament a lot more fun.
This is a really good project to try if you're new to lace knitting. The pattern is not that difficult, the project will be over quickly and your ornament will still look great even if you don't follow the pattern exactly perfectly.
You could also use this pattern to make an inexpensive gift of ball ornaments you already own or that you buy from a discount store. One skein of lace weight yarn would make a bunch of these with little expense and a big wow factor.