Place the frozen watermelon chunks into the blender, filling it about three-quarters full for optimal blending.
Add the ice cubes on top of the watermelon, creating a layered look that helps with even blending.
If you like extra sweetness, drizzle in a teaspoon of honey over the ice.
Secure the lid on the blender tightly and start blending on high speed, listening for a smooth, icy crunching sound as the ingredients break down.
Blend until the mixture is uniformly slushy and every piece of ice and watermelon is finely blended, about 30-45 seconds.
Stop the blender and check the texture; it should be smooth yet granular, with tiny ice particles suspended evenly throughout.
If the slushie is too thick, add a splash of cold water or more watermelon chunks and blend briefly to loosen it; if too watery, sprinkle in a few more ice cubes and blend again.
Pour the chilled watermelon slushie into glasses, allowing the vibrant pink color and icy texture to shine.
Garnish with a small watermelon wedge or a sprig of mint if desired for a decorative touch.
Serve immediately with a straw or spoon, enjoying the cold, refreshing burst of summer flavor.
