Easy
Hot Buttered Rum
In a large mug pour 6 or 8 ounces of boiling water; add a rounded tablespoon of dark brown sugar and stir to dissolve. Add a cinnamon stick and a generous piece of clove-studded lemon peel. (What I typically do is just throw in a slice of lemon and 4 or 5 cloves) Stir in 2 or 3 ounces of rum (preferably dark Jamaican) and top with a butter pat and grated nutmeg.

Easier
Mulled Cider
1 tbsp Mulling Spices in a saucepan with 1 litre of apple cider & simmer for 10-20 minutes. Serve hot with a cinnamon stick for garnish.

Easiest
Eggnog
Buy eggnog at store
Add brandy