To make the fruit easier to juice, roll firmly on the counter with the palm of your hand to loosen up the flesh.
Cut the fruit in half crosswise and juice it using a handheld juicer, food processor attachment or whatever tool you happen to favor.
Using a small ladle or a small pitcher with a spout, pour the citrus juice into ice cube trays. Each standard-sized ice cube will contain about 2 tablespoons of liquid. However, I suggest measuring the capacity of your ice cube tray to be sure.
Freeze until solid. Juice will freeze to a stage that is slightly softer than regular ice cubes. Remove cubes from the tray and place in a freezer resealable bag.
When you are ready to use the juice, remove the number of ice cubes from the freezer that you desire and defrost them.