Combine sugar and water in a saucepan. Stir over medium-high heat until sugar dissolves. Bring to a gentle boil, boil gently for 3 minutes. Set aside to cool. Stir in lime juice, rum and coconut water.
Three-quarter fill ice cube holes with fruit, flowers and leaves. Pour over the rum mixture to fill the holes. Freeze overnight.
Pile ice cubes into glasses. Top up with lime soda, lemon lime & bitters, ginger beer or soda to serve.
Tip The ice cubes will keep in the freezer, turned out into an airtight container for 4 months.