Add the frozen strawberries, lime juice, simple syrup, and water to a blender.
Add on the lid and blend for 20 seconds. Taste and add more sweetener or lime juice according to taste. If too thick, add a little more water.
Pour the mixture into cocktail glasses.
Garnish with sliced strawberries or a lime slice, then serve.
Notes
The water can be substituted for coconut water, tonic water, or lemon-lime soda. If using a sweetened one, you may want to reduce the simple syrup in the recipe.