You have got to try this one.
Put 5 drops of food coloring into a balloon and fill it up with water. Tie it up, toss it outside and let mother nature take her course. In a couple days they will be frozen enough to peel off the ballon outside. You will be left with a shimmering and colorful ice globe.
Note: They take longer to freeze completely through than you would think. Be patient and it will all work out. I was impatient with one batch of mine and they ended up having a hollowed out look and we put candles inside, but I would rather they be frozen throughout.
Be aware, You’ll want to make about a zillion of these, it’s kind of addicting.