Place the coarse salt in a shallow dish. Rub a lime wedge around the rim of each glass, then gently dip the rims into the salt to coat evenly. Set aside.
Add the fresh lime juice, tequila, triple sec, simple syrup, and ice into your blender. Secure the lid tightly.
Blend on high for about 30-45 seconds until the mixture is icy, frosty, and smooth, with a slushy consistency. You should hear a loud whirl and see the ice pulverize into tiny particles.
Stop the blender and check the texture—if it’s too runny, add a handful more ice and blend briefly again until you reach the perfect slush.
Pour the frozen margarita into the prepared glasses, filling them generously to showcase the icy, frosty surface.
Garnish each glass with a fresh lime wedge and, if desired, a sprig of mint for a fragrant touch.
Serve immediately with a straw or spoon, and enjoy the cold, citrusy refreshment!