First of all, avoid sugary bases for drinks, including syrups, regular soda, and juice "imposters" (juice "drinks" that aren't 100% fruit juice).
Skinny Screwdriver
This traditional cocktail gets a makeover when you use diet lemon-lime soda to halve the calories and provide a flavorful, fun fizz. Combine 8 ounces of diet lemon-lime soda with a shot (1.5 ounces) of vodka and a shot of orange juice. Pour over ice, garnish with orange slices or orange peel, and enjoy for just 138 calories.
Nothing screams summer like fresh, juicy peaches. In a blender, combine a shot of white rum, 1 medium (2-2/3 in diameter) chopped & peeled peach, 1 cup cold Ocean Spray Diet Cranberry Juice, the juice of 1 lime, and a handful of ice cubes. Sip this frozen fruity concoction for a mere 171 calories.
Skip the usual fat- and sugar-laden piña coladas and swap out several high-calorie ingredients to create a lightened-up version of this popular Caribbean cocktail. To prepare, throw ½ cup frozen pineapple chunks, ½ cup pineapple juice, 1 shot coconut-flavored rum, ¼ cup light coconut milk into a blender. Blend until smooth, add 3-4 ice cubes, and blend again. This lighter version clocks in at 244 calories, a far cry from a typical piña colada, which contains over 500 calories.
Who would think a cotton-candy inspired drink would be low-calorie? To whip up this sweet sip, combine ½ cup seltzer water, 2 Tbsp pineapple juice, 1 shot vanilla vodka, and 1 tsp of grenadine and serve over ice for a measly 132 calories.
An easy, low-calorie adult beverage for chocolate lovers: Simply prepare 1 packet of diet hot chocolate (25 calorie version) according to packet directions, add 1.3 ounces Bailey's Irish Cream, and pour over ice for a slim 119 calories.
Source: http://www.fitday.com/fitness-articles/nutrition/skinny-summer-cocktails.html?utm_medium=Email&utm_source=ExactTarget&utm_campaign=