1. In a blender, combine citrus fruit, sugar, and tequila.
2. Add ice cubes to blender to crush them. 
3. Frost glass rims with sugar, if you wish. Use 4 large glasses that can contain at least 500 mL (2 cups).
4. Pour citrus juice-tequila blend into the glasses.
5. In one quick movement, turn a bottle of beer upside down into each glass.
6. Garnish glasses with orange and lime wedges. Serve.

Chef's secret

To frost glasses, rub rims with a slice of orange or lime then flip and turns rims in a small dish filled with sugar,