Use a 100% agave Blanco or Reposado tequila, fresh squeezed lime juice (use small Mexican limes, they're a little sweeter than the typical American variety), and a quality triple sec (Cointreau, or Grand Marnier, if you prefer).

Spread a little bit of coarse salt onto a small plate, rim an oversized cocktail glass with a wedge of lime and roll the rim through the salt. Make sure to just coat the outside of the rim, you don't want any salt on the inside or it will fall into the drink.

Mix the liquid ingredients together with plenty of ice in a shaker, shake thoroughly and strain into the prepared glass. Sip.