Jello Shots Techniques: Alcohol Concentration When making jello shots, what proportions do you typically use?

For hard liquor like Gin, Tequila or Vodka, I've been using 1 part hot water to dissolve the jello and then 1 part cold spirits.  Some of these seem stronger than others.

For a liqueur like Pama (only 17%), it froze in the freezer and I had to wait for it to thaw.  I used 1 part cold Pama, but the general consensus was that the shot needed to be stronger.

The Jello seems to gel just fine.
You are probably fine with the 1:1 ratio for your likely 80 proof liquors.  For weaker liqueurs just add more.  You probably want 2:1 if you can get it to work.