For 1 martini: In a shaker, put a handful of blueberries (about 1/3 cup). Add sugar, about 2 teaspoons (or more if you like.) Next, add 2 shots of vodka, a splash of Hendricks Gin, and the juice from 1/2 of a lime.
I really love this hand mixer. They're made by Braun and I consider it a kitchen must have. They're only about $15, and it also comes with a small attachment bowl -- like a little mini food processor -- which I find perfect for making things like quick salad dressings. This is faster than even getting out your muddler. When done, you simply rinse it clean with hot water.