Start by preparing your cocktail glasses: rub the rims with a lime wedge and dip them into coarse salt to coat the edges. Set aside.
Add freshly squeezed lime juice, tequila, frozen fruit, simple syrup, and triple sec (if using) into your blender. This mixture forms the flavorful base for your margarita.
Crush or add crushed ice to the blender, then blend on high until the mixture is thick, gritty, and slushy, with tiny icy shards and vibrant color blending together. This should take about 30-45 seconds.
Stop the blender and check the texture. It should be cold, frosty, and slightly granular, with no large chunks remaining. If it’s too thick, add a splash of water and blend briefly again.
Pour the chilled, icy margarita into the prepared glasses, filling them generously to showcase the frosty, colorful mixture.
Garnish with a lime wedge or a slice of fresh fruit on the rim for a finishing touch.
Serve immediately with a straw or sip slowly to enjoy the icy, tart, and sweet flavors melting together.