Pour some simple syrup in a small bowl and the shredded coconut in another small bowl.
Dip the top ¼ or so of your champagne glasses in the simple syrup and then in the shredded coconut making sure the rim is well coated. Set aside to dry a little
Fill each champagne glass with 1 ½ ounces of EACH pineapple and coconut juices.
Fill the rest of the way with the champagne or Prosecco.
Serve immediately.
To Make Simple Syrup
Simple Syrup is a 1:1 sugar-water ratio syrup.
To make, combine equal amounts in a sauce pan (e.g. 1 cup sugar one cup water) and then bring a simmer stirring until all the sugar is dissolved.
Chill completely in an air tight container until ready to use.