Changed some light bulbs yesterday and tried this! Didn't have napkin rings, so I set the bulbs on burnt down tea lights! Super cute and o, so simple!you need to break the bottom of the bulb very carefully or the whole thing will crack.
Do you have old light bulbs that are not broken? Instead of just throwing them away, you can repurpose them as some creative things. Check out this list of Creative Light Bulb DIY Ideas and try one of them.