In the past, I decorated clear Christmas bulbs by dribbling glass paint inside the bulb and rotating it until the colors interacted to make an abstract 'watercolor' painting. That's an easy project and produces original bulbs each time. No power involved there and very little risk to limbs.
Then again, using the camera to capture reflections indoors during the frigid temperature outside seems the least risky of all. See the newest one here on my Art Blog.