Great for summertime, or anytime of year if you freeze your blueberries. I made this for the Super Bowl this year as the themed cocktail (because of the color) for the two teams (Giants/Pats). Next time I might muddle it with a bit of fresh mint as well.
Place blueberries and agave in a cocktail shaker or jar with a tight-fitting lid. Using a wooden spoon, muddle the blueberries to crush them slightly and combine with the agave. Add vodka and ice and shake to combine and chill vodka.
Pour mixture into a cocktail glass or tumbler and top with ginger ale or soda. Enjoy!