Mix salt chilli and paprika powder together on a medium-sized plate.
Place remaining ingredients and a handful of ice into a blender and blend until smooth.
Pour to just below salted rim in glasses and garnish.
Tip: for a virgin cocktail, simply omit alcohol, double watermelon and lime juice and add 60ml of orange juice.
Tip: if your watermelon isn’t as sweet as it could be, add a tablespoon of sugar syrup at the blending stage.