You can add more flavor to your mixed drinks by using flavored vodkas without worrying about increasing the drinks' calorie content. Choosing a light vodka can decrease the calories even more. Don't forget that any mixers you add, such as soda or fruit juice, will further increase the calories in your drink.
Most regular vodkas, including flavored vodkas, have about 60 calories per ounce, unless you increase the proof of the alcohol. An ounce and a half of 94 proof vodka has 115 calories, and the same amount of 100 proof vodka has 125 calories. Choose a light flavored vodka instead and you'll only be drinking about 78 calories per 1 1/2 ounces of vodka.