Prepare the Lime Juice: Roll the limes on the countertop with your palm to loosen the juices. Cut the limes in half and use a juicer to extract the juice until you get 4.5 ounces (we cheat & purchase at our neighborhood grocery).

Mix the Drink: In a cocktail shaker, combine the tequila, freshly squeezed lime juice, and Cointreau or Grand Marnier. Fill the shaker with ice until it covers the liquids.

Shake the Cocktail: Secure the top of the shaker and shake vigorously for about 15 seconds to mix and chill the drink thoroughly.

Serve: If you like a salted rim, run a lime wedge around the edge of the glass and dip it in salt. Strain the mixture into a chilled margarita glass for a "straight up" drink or over ice in a rocks glass.

Garnish and Enjoy: Garnish with a lime wheel or wedge. Serve immediately.