JC's Margarita Recipe

Friends say that I make good margaritas. Here's how:
1 cup sugar (confectioner's or granulated)
1 cup lime juice (preferably fresh-squeezed)
1 cup Triple Sec or other orange liqueur such as Cointreau, or 1/2 cup orange juice
2 or 3 cups tequila
Use a "cup" of any size. For one drink, use a large measuring spoon or a shot glass. Or use a 1/2-cup "cup", and save anything left over in the refrigerator.

Combine the ingredients in a blender. Blend at low speed until the sugar is dissolved, 30 seconds for confectioner's sugar, 1 minute for granulated. If you don't have a blender, stir it all with a spoon or whisk, let it sit for a while, and stir it again, untils the sugar is all dissolved. Fill your glass with ice, pour the mixture over the ice, and drink.

Notes:
First, all the above proportions are approximate. Try this recipe first, then adjust the proportions to your taste. For a crowd, the above are about right, but you might to go a bit light on the sugar, and have a shaker of powdered sugar nearby for people who like theirs sweet.
Salt?
My wife, who is a saltaholic, agrees that this margarita tastes fine without salt. Then she adds salt. If you like salt, add it according to whichever salt ritual you like. If you don't like your food salty, try it without salt.
Lemon?
Some recipes call for lemon juice instead of or in addition to lime juice, but it's not a real margarita without lime juice. A 50/50 mixture, 1/2 half cup each of lime and lemon juice, works, and most people can't taste the difference. If you can get key lime juice, try it. Key limes have a flavor between green limes and lemons, and they make fine margaritas.
Orange
Triple sec, CuraƧao, Cointreau and Grand Marnier are all orange-flavored liqueurs. The difference is that triple sec is really just grain alcohol with orange added, so it adds little flavor other than orange. The others are orange-flavored brandies, so they adds a brandy "richness", which most people like better than triple sec. There are also other orange-flavored liqueurs that work well. Try any that you like. Plain (fresh-squeezed) orange juice is also good, but use only half as much, because triple sec and the orange brandies aren't all that strongly orange flavored. The result will be slightly less alcoholic. If this bothers you, add a bit more tequila.
Sugar
After the first time, you should adjust the amount of sugar to your taste. If you like tart things, you'll like your margarita with less sugar.
Commercial lime juices.
If they're simply pasteurized lime juice, they're not as good as fresh-squeezed, but they're good enough. There are also sweetened lime juices, such as Rose's. These can be used, and they tend to be on the tart side, so you'll probably want to add a bit of sugar. You'll have to experiment to find the right amount for your taste.
Fresh-squeezed
If you can, get whole limes (and maybe lemons and oranges), and squeeze them yourself. There's a farmer's market near where I live that squeezes citrus juices in a machine in the back; this is second best, and very convenient. Commercial citrus juices are third best.
Lime peel/zest
The thick green outer layer of a lime (or the colored outer layer of any citrus fruit) is referred to as "zest" by chefs. This is an excellent addition to your margarita, but you'll have to prepare it a day ahead. You'll need a moderately fine grater designed for this. Grate the zest of a lime into a glass or bowl, and add the tequila. Let them marinate overnight in the refrigerator. Using a tea strainer or similar, strain the juice into your blender as you make the margaritas. It's a bit more work, but it's the best margarita. I've also used orange and lemon zest, and they're both good.
Tequila
Use real tequila, made from real agave azul (blue agave). You'll be glad you did. Don't substitute other kinds of booze. Without tequila, it's not a margarita. I've had a similar drink made with whiskey and lemon juice. It's called a whiskey sour. It's good, too, but it's not a margarita. A margarita has tequila as the main kind of alcohol, and lime juice for the tart citrus flavor.
Commercial margarita mixes
No!!! Don't waste your money. Spend it on more expensive tequila instead, a variety whose label says "100% de agave".
Leftovers
Any leftover margarita keeps fine in the refrigerator. It's really good for breakfast instead of orange juice. It will separate somewhat overnight, especially if you used orange juice, so stir it before you drink it. If it's in a covered container, you can just give it a shake. One note, however: Since it's cold, it won't melt ice cubes very well. You might find it too strongly lime flavored. It is alcoholic limeade, after all, and the lime juice should be diluted 4 or 5 times. The above recipe only dilutes it about 3 times, and the ice cubes do the rest. So you might want to mix in a little water. If this offends your sense of macho, dilute it with a little more tequila instead.
The original recipe
The original margarita recipe didn't include sugar or ice. The Triple Sec did add some sugar, but it was extremely tart. Margaritas didn't catch on until people learned to add sugar (and ice). My mother-in-law (RIP) liked the original margarite, in one of those conical glasses, with lots of salt. But most people like the above recipe better. For a crowd, I'd recommend the full cup of sugar. For yourself, figure out the ratio that you like best. You might have to drink a lot of margaritas to learn the optimum ratio, but it's worth it.

There was a good article on margaritas in Cook's Illustrated a while back. They pretty much said all of the above, except I don't think their tasters left any leftovers. If you can find the article, read it. Or subscribe and read all their articles. Before you know it, your friends will think you're a gourmet chef.

-- John Chambers