Some of the best cocktails are the easiest to make, and author Kara Newman figured out the secret--using equal parts of the main ingredients and adding a dash of bitters or a splash of seltzer to gild the lily. Take the Cucumber Gimlet: Combine one part each vodka, lime juice, and lemonade; 2 cucumber slices; then garnish with a basil leaf And beverages like this are a breeze to size up for parties--just double, triple, or quadruple the proportions...