Combine the fresh lemon juice, water, simple syrup, and a pinch of salt in a measuring glass or small bowl, stirring until well mixed.
Add the mixture to your blender along with the ice cubes, ensuring there's enough space for blending.
Secure the lid on your blender and blend on high until the ice is fully crushed and the mixture appears thick, frosty, and slightly slushy—about 30 to 45 seconds.
Check the texture—if it's too thick, add a splash more water and blend briefly; if too thin, sprinkle in a few more ice cubes and blend again.
Pour the vibrant, icy slushie into glasses, allowing the bright color and frosty surface to shine through.
Serve immediately with a straw or garnish with a lemon wheel for extra visual appeal and a fresh citrus aroma.