While playing around with an Arduino board a few weeks ago, I was feeling a little blinded by the very bright RGB light on the board. Hunting around the house for something to diffuse the light, I found a handful of old ping pong balls - perfect! I snipped one in half, and lay it over the top of the LED, and it was just right for looking at.
I was still looking at the remaining ping pong balls, and wondering where to put them away, when I spotted a string of fairy lights looking unloved. On went the figurative lightbulb, and the Lucky Charms appeared!
You will need:
A string of fairy lights (and batteries if required)
A pair of scissors
A handful of ping pong balls (I only had enough for every other light, it doesn't matter if they're all covered or not)
Step 1: Piercing
Now, I used scissors, but the teacher in me suggests that you should be thinking safely, and using something like a darning needle or similar, to make the initial hole in the ping pong ball.
You need to pierce each of them, and then file/cut out the hole so that it is slightly smaller than the diameter of the light bulb. I used the blade of a pair of scissors, and turned it around in the hole, to carve out the excess plastic.
Be careful with this - I slipped on the one in the top right, and made a huge slot, luckily, it wasn't so big it doesn't fit now!