I love this experiment for a number of reasons: It's fun, it's easy, it's a great way to explain changes in states of matter, and it looks like magic! While this activity is very easy as is, you can even make it a little more simple by simply using an empty two liter bottle of soda filled about a fourth of the way full of water and a coffe filter. Tear the coffee filter in half, place it on top of the bottle, light it on fire, let it burn for a second, then push it into the two liter carefully, then cap it. After that, you just need to squeeze the bottle to add high air pressure and you'll see a cloud form that way too. It won't be as impressive as the one shown here, but it still works if you don't have the other materials.