how do you get the fog effect from dry ice?

You put it in water. Just don't do it in a small confined space, like a bedroom or office without opening doors/windows for ventilation, the fog is actually made of carbon dioxide and can actually cause you to suffocate if confined. I saw it on an episode of C.S.I. once, and looked it up to verify. Very cool huh?

Put it in a container of water; but make sure the container is much larger than the piece of dry ice since the liquid will bubble up and might overflow, which is something you deifnitely don't want.

You don't PUT it in water...you put water on it - you are not supposed to touch dry ice with your hands.

But it's quite simple...just add water...I forget the chemical reaction but it works so well...love it!

Put the dry ice in any liquid....

I use to sell this at a Mardi Gras store. You just add water. But DO NOT TOUCH it because you will burn yourself even though it is cold.

by placing it in water

I believe you put it in water.

just add water. but don't add it to water in a two liter bottle and then screw the cap on, you'll wish you didn't....