This recipe is adapted from Dave Arnold's book Liquid Intelligence. It is designed to be adapted to work with a variety of spirits.
Dissolve sugar in alcohol.
Fill blender with ice.
Pour liquid ingredients over ice and add a pinch of sea salt.
Pulse blender a few times to break down ice and then blend on high for 15-20 seconds.
Dave Arnold recommends adding sugar to your alcohol beforehand. You can add 159 grams of sugar to a 750 ml bottle of alcohol at 40-50% ABV if you want to have a bottle dedicated to making frozen drinks. That's not such a bad thing.
Superfine sugar is best because it dissolves quickly. You can use granulated sugar, but it will take longer to dissolve.