This first one I made simply by squirting red and green (in alternate stripes) down the insides of a basic glass ornament. The only trick to this one is to add enough paint that it will flow down the sides of the ornament, but not so much that it will blend with the other color. If you're patient, you can do one color, let it dry, and then do the other color.
This one is pretty basic - I used a paper shredder to shred the colors I wanted (the color of my college sorority, in this case), and then stuffed the ornament. Basic, but there's nothing wrong with that!
This one is honestly one of my favorites. I took tinsel (that came in a gift bag I had gotten, yay for reusing stuff!) and added it to the bulb. I then used a great set of 3D stickers to decorate it.
What are ways you've used those basic glass ornaments? Which one of the above is your favorite?