Wash the strawberries thoroughly and remove the stems. Place them in a blender or food processor and blend until completely smooth. For an extra-smooth lemonade, strain the puree through a fine-mesh sieve to remove the seeds.
Combine the sugar with 2 cups of water in a small saucepan. Heat over medium heat, stirring frequently until the sugar dissolves completely. Once dissolved, remove from heat and allow the syrup to cool to room temperature.
Squeeze enough fresh lemons to yield 1½ cups of juice. Strain the juice through a fine-mesh sieve to remove seeds and excess pulp. Fresh lemon juice provides the vibrant flavor that makes homemade lemonade so refreshing.
Pour the lemon juice into a large pitcher. Add the cooled simple syrup and strawberry puree. Stir everything together thoroughly until the mixture is fully combined and evenly colored.
Pour in about 2½ cups of cold water and stir well. Taste the lemonade and add additional water if needed to achieve your preferred sweetness and strength. This flexibility allows you to customize the flavor perfectly.
Place the pitcher in the refrigerator until thoroughly chilled. When ready to serve, pour the lemonade over ice and garnish with fresh strawberry slices and lemon rounds for a beautiful presentation.