Measure out the lime juice using a measuring cup, ensuring it's freshly squeezed for bright, tangy flavor.
Pour the lime juice into the blender, followed by the tequila and sweetener, creating a vibrant liquid base.
Add the ice cubes to the blender, filling it up to roughly the halfway point, to achieve a snowy, slushy texture.
Secure the lid on the blender and blend on high speed for about 30-45 seconds until the mixture is smooth, frosty, and uniform in appearance.
Pause the blender to check the texture; it should be thick and icy but scoopable with a spoon or straw.
Pour the frozen margarita slushie into chilled glasses, garnishing with lime wedges if desired for a festive touch.
Serve immediately with a straw or spoon to enjoy the crisp, icy texture and bright citrus flavor.