One of the hundreds of -tini variants, guava martinis, or guavatinis, use vodka as the base and -- you guessed it -- guava nectar as the modifying agent, the ingredient that gives a cocktail personality. Guavatini shares little with its derivation drink save a suffix, but it has an advantage over the martini: freedom. Using the basic cocktail formula -- spirit, modifying agent and special flavorings -- make your own take on a guavatini to give the drink character. Start with a basic guavatini and build from there, following one loose guideline: Cocktails typically have five ingredients or less.
Muddle fresh herbs against the inside of the cocktail shaker, if desired. Guava works well with floral herbs, notable mint, lemon balm and kaffir-lime leaves; if you like spice, rub peeled ginger inside the shaker.
Add 1 part vodka to a cocktail shaker filled with crushed ice. Try a fruit-infused vodka that matches the modifying ingredient for an extra layer of flavor. Almost any tropical fruit works, but guava nectar pairs seamlessly with pineapple, coconut and passion fruit.
Add 1 part guava nectar to the shaker. Use a brand with little or no added sugar; guava nectar is also sold as "guava juice."
Add 1/2-part special flavoring, which can be bitter, sweet or sour. Your juice of choice, a touch of warm honey or a favorite liqueur all work here.
Salt or sugar the rim, if desired. Spread the salt or sugar in an even layer on a plate and lightly moisten the lip of the martini glass; dip the rim of the glass in the salt or sugar. You can use crushed candy in place of sugar to add a twist.
Shake and pour, using the strainer of the shaker. Garnish the guavatini with an ingredient that ties into another component of the drink. For example, if you use mint, garnish with a fresh mint sprig; if you used a citrus liqueur, garnish the rim with a wedge of the liqueur's base fruit.