In a cup big enough to fit a handheld blender, or in a regular blender, place the lemon juice, strawberries, and 1 cup of water. Blend it well. Strain if desired.
Transfer the mixture to a pitcher. Add the remaining water (2⅓ cups) and sugar. Mix it well until sugar is dissolved.
Taste it and adjust it to your liking, if necessary. Add ice and serve it immediately.
Notes
People have different tastebuds, so feel free to adjust this recipe to your liking.*More lemon juice if you want it sourer.*More strawberries if you want the strawberry flavor more pronounced.*More sugar or sweetener if it's not sweet enough for you.*More water if the taste is too strong.