With Gin (for a cooler) or Rum (for a mojito):

Muddle (crush with the back of a spoon), 6 mint leaves, ½ a lime, and one shot (or so) of your liquor of choice at the bottom of a cup. Add 4-6 cucumber slices. Pour over ice and finish with tonic water. Let it sit for a few minutes so the flavors combine.  Cheers!