The single most important ingredient is fresh lime juice. Use any gadget you like--just please don't twist open a screw cap. For parties, juice the limes ahead and fill a squeeze bottle to keep at the ready.
That's not a typo--and no, you won't miss it. We prefer light agave syrup for its complementary flavors (and shared origin) with tequila.
GO FOR SILVER
Always drink tequila made from 100 percent blue agave. It just tastes better. In Margaritas, use onlyblanco (a.k.a. silver or white) tequilas, which have a peppery, vegetal kick that won't get buried when mixed. Save your aged reposados for sipping.
TAKE IT WITH A GRAIN OF...
Salt brings out the flavor in everything, but too much can be overwhelming. So we only salt halfway around the rim and are careful not to get any in the drink.