Wash 4-5 fresh limes thoroughly under running water.
Cut the limes in half and squeeze the juice using a citrus juicer or by hand, collecting the juice in a bowl or jug.
If desired, add sugar or honey (2-3 teaspoons) to the lime juice and mix well to sweeten the taste.
Pour the lime juice into a serving glass, add 200-250 ml of cold water, and stir well.
Add ice cubes to the glass and garnish with a slice of lime or a sprig of mint, if desired.