Prepare your glasses: If desired, run a lime wedge around the rim of your margarita glasses. Dip the rim into a plate of salt or sugar to coat. Set aside.

Combine ingredients: Add the ice cubes, tequila, orange liqueur, fresh lime juice, and agave nectar (or simple syrup) to your blender.

Blend until smooth: Secure the lid and blend on high speed until the mixture is smooth and slushy, with no large ice chunks remaining. If it's too thick, add a tablespoon of water or more lime juice. If it's too thin, add a few more ice cubes.

Taste and adjust: Carefully taste the mixture. If you prefer it sweeter, add a little more agave nectar. If you like it tarter, add a bit more lime juice. Blend again briefly to incorporate.

Serve immediately: Pour the frozen margarita into your prepared glasses. Garnish with a lime wedge, if desired.

Enjoy your perfect frozen margarita!