This is the fairly standard, but popular recipe that I've used for years.
1 litre grapefruit juice
2 litres sparkling lemon
2 litres ginger ale
1 litre cold tea
mint, slices of orange, ice.
Chill liquids, add all, mix and serve in a glass bowl with a ladle.
For the non-alcoholic version, as above.
This recipe can be doctored with rum, wine (sparkling is nicest), or gin. Vodka doesn't contribute flavour, and so is not recommended.