Old Caribbean Recipe...
"One of sour, two of sweet, three of strong, and four of weak."

Mix all the ingredients in a jug or container. Taste and add some sugar if desired. Serve in glasses with ice and garnished with fresh fruit, if liked.

In the Caribbean the mixture in the jug is usually kept cold with large chunks of ice - created by freezing water in tins or pans and then breaking it up. The mass or large chunks seems to take longer to melt, and obviously even better results can be achieved by using already-cold ingredients.