Fill each glass two thirds full with the crushed ice. If the ice is in cubes, place into a plastic freezer bag, seal and whack with a rolling pin to break it up.
Place the rest of the ingredients into a blender and whizz up until well combined.
Pour over the crushed ice in each glass. Add a straw to each glass and garnish with your choice of colourful decoration, perhaps a slice of pineapple and cherry.