Pour a small amount of fresh lime juice into a shallow dish, then place your coarse sea salt in a second shallow dish right next to it. Run the lime juice around the rim of your glass in a complete circle, making sure the entire edge gets wet.

Gently dip the wet rim into the salt, rotating the glass so the salt adheres evenly all the way around. Pat away any excess salt that sticks to the outside of the glass below the rim.

Add a generous handful of ice cubes to your cocktail shaker, filling it about halfway. If you have time, fill the shaker with ice and let it sit for 30 seconds before pouring your liquid ingredients into it.

Using a jigger, measure out 2 ounces of quality silver tequila and pour it directly into the ice-filled shaker.

Measure 0.5 ounce of triple sec or Cointreau and pour it into the shaker with the tequila.

Cut your lime in half and squeeze both halves vigorously using a citrus juicer, extracting 1 ounce of fresh juice. Pour into the shaker.

If you like your margaritas sweeter, add 0.25 ounce of agave syrup or simple syrup to the shaker now (optional).

Close the shaker tightly, making sure the cap is sealed completely, then shake hard for 10 to 15 seconds until the shaker feels ice-cold in your hands.

Place your fine mesh strainer over the top of the shaker and carefully pour the contents into your salt-rimmed glass.

Drop a lime wheel into the glass for garnish if desired, and serve immediately.