Suspend pieces of fruit in the cubes. Cherries, blueberries and other small berries, and slices of lemon or lime look especially pretty and provide a treat that won't alter the flavor of the beverage.
Add complimentary flavors. You can dilute juices or baking flavorings like vanilla by adding water and freezing. For stronger flavors, pour pure juice into the ice cube tray. As the ice cubes melt they will add more complexity to the drink. Experiment with other liquids like coffee or liqueurs.
Embellish drinks with edible flowers. You can either encase them in water and freeze them in ice cube trays, or simply freeze the flowers and use them as ice cube substitutes.
Add food coloring. Create decorative ice cubes that won't alter flavors by adding gel color or food coloring to ice cube trays. Try not to mix the color in completely so that the ice will have a dramatic swirled or polka-dot effect.