This is a super easy! Sorry for the flash on the ornament. Not the best of my photography skills.
What you need:
Paint in a tube
Clear plastic ornament (We got ours from AC Moore $1)
This ended up being a great activity for Josh. My usually happy boy was quite the little grump. He actually banged the ball on the table. I guess that helped with his aggression. lol The ornaments are soft so I let him do it. Usually I would suggest shaking them until the paint covers the inside of the globe.
It turned out pretty. I love it!