Add boiling water to the pack of Jello first, then 3/4 cup cold alcohol and 1/4 cup cold water. Mix and set in small cups, preferably the kind that are wax-coated (the kind they use for ketchup at McDonald's).
If you use the small plastic medication cups the Jello sticks and you won't be able to pop the shot in your mouth. With the wax paper cups you can squeeze the Jello shot into your mouth with no waste. Enjoy!