01 - Place cubed watermelon in blender and process until completely smooth, forming a uniform puree.
02 - Pour watermelon puree through fine mesh sieve into large pitcher, pressing with spoon to extract juice and remove excess pulp.
03 - Add fresh lemon juice and sweetener of choice to pitcher. Stir vigorously until sugar or agave completely dissolves.
04 - Pour in cold water and mix thoroughly. Taste beverage and adjust sweetness or lemon acidity to personal preference.
05 - Refrigerate for minimum 1 hour to blend flavors, or serve immediately over ice cubes for instant refreshment.
06 - Decorate glasses with fresh lemon slices and mint sprigs just before serving for visual appeal and aroma.