Here is a yummy white martini called the Liquefied Ghost Cocktail - from HGTV - I am posting the exact way the say to make it below, but note of caution, they state to add the soda in a shaker and shake. Ummmm yeah,  been there done that!  I would like to suggest if you don't want to be cleaning up a ghostly mess at your party, you might want to shake lightly or add the soda after the pour. 

Get creative.  You can also make this drink for other seasons and change the name.  It can be part of a trio of red, white, and blue cocktails for the Fourth of July, it can be for an all white Summer party or all white wedding. They sky's the limit! 

Ingredients:

2 oz. vodka 

1 oz. vanilla simple syrup 

1 oz. cream 

2 oz. club  or cream soda

Preparation:

Mix vanilla simple syrup, cream, vodka and soda together in a cocktail shaker, then serve in a chilled martini glass.

For the vanilla simple syrup, you can purchase vanilla simple syrup at a liquor store, but I found if you prefer, you can make your own.

Ingredients:

2 cups sugar

1 cup water

2 vanilla beans

Preparation:

Bring the sugar and water to a boil in a saucepan.

Split the vanilla beans lengthwise into halves and place in a heatproof jar or bottle.

Pour the hot syrup over the vanilla beans and let stand for 8 to 10 hours.

Store in the refrigerator for up to one week.