Once even the first inkling of warm weather starts cropping up after such a long and vicious winter, my thoughts immediately turn to tonic. There are some bottled versions that I like (though nothing that comes in plastic will do) but assuming you possess a soda siphon, the real way to roll is making your own. This also allows for creative license to help deal with things like snow while you're trying to make tonic, by upping the warm, wintery spice profile.
The basic recipe here comes courtesy of Maggie Savarino's Seasonal Cocktail Companion, which is a great source for creative homemade booze-projects.
4 cups water
2 1/2 cups sugar
3 tablespoons cinchona bark
3 tablespoons citric acid
3 tablespoons dried citrus peel (homemade is easy; mine was an equal mix of lemon and orange)
1 tablespoon coriander
1 teaspoon juniper berries
1 teaspoon cracked grains of paradise (use 1/2 teaspoon of white pepper if you can't find these)
1 teaspoon crushed cinnamon
Bring the water to a boil, add the sugar, stir until dissolved, then reduce the heat to low. Add the remaining ingredients and simmer for 30 minutes. Let cool, double-strain, and keep refrigerated in an airtight container.
Applications are obvious - gin and vodka would be the most straightforward, but I encourage you to explore others. Pisco and aquavit are among my favorites. For any of the above, use about 1/2 oz of tonic syrup to 2 oz spirit, topped off with 3-4 oz of soda water to taste.