This is for the purists, there are some decent variations on the mojito, but I've had too many bad ones to trust the average bartender. Cubans that I've talked to prefer white sugar and white rum. Apparently there is some myth about turbinado (raw) and dark rum (my favorite modifications) having "impurities". I've found that Mexican mineral water, such as Topo Chico works well. Good variability in bubble size, good taste, widely available here in Austin. Get yourself a lime/lemon squeezer. It will practically turn the lime inside out. They make the juicing of limes quick, and they bring out some of the oils in the skin which adds to the flavor. Use key limes, the smaller, juicier Mexican limes.

The biggest mistake bartenders make is shaking, stirring, or otherwise mixing the drink after all the ingredients are together. DON'T. That is for the drinker to do with their straw. It is supposed to be stratified.

In a collins glass drop 8-12 mint leaves and one tablespoon of granulated sugar. Using a muddler or wooden spoon, break up the mint. Get after it. Add the juice from one key lime. Add Rum. Fill glass with ice, and top with the soda water. Garnish with a mint leaf, and half the lime. Do not stir. It is supposed to be stratified. Drink it with a straw. If you want sweet drink off the bottom, if you want dry drink off the top. Drink. Repeat.

The variations I like best are using basil for some or all of the mint, and honey instead of sugar. Oh, and doubling everything into a pint glass.