How do you make Jell-O shots?

I’ve never made them before and want to give it a try.

The general consensus I have is to just follow the recipe on the back of the jello box. But it’s the cold water part that gets me a lil confused. Is it necessary? I’ve seen some people chill their alcohol. Some people let their mixture cool for a few minutes then do the alcohol. Could I just add a few ice cubes to cool my mixture down then go ahead and add my alcohol?