Wet the rim of a margarita glass or tumbler by rubbing a lime wedge around its circumference. Rotate the rim of the glass in kosher salt spread on a flat plate. Fill the glass about halfway with ice cubes.
In a cocktail shaker filled with ice, combine tequila, triple sec, freshly squeezed lime juice, and prickly pear syrup. Shake vigorously, then strain into the prepared glass. Garnish the rim with a lime slice or wedge. Serve immediately.
This is the prickly pear syrup I use for this recipe. It keeps for quite a while in the refrigerator after opening. Use leftover syrup for topping pancakes or waffles!
Definitely squeeze fresh lime juice rather than using bottled lime juice. It makes a huge difference in flavor and quality.
Like with anything else, you get what you pay for. Using a higher quality tequila will result in better tasting margaritas. You don't necessarily need to splurge for a top shelf tequila like Patron. Jose Cuervo will work just fine, but avoid cheaper, low quality tequilas if possible. Silver or blanco tequila is ideal for margaritas as it hasn't been aged as long.