While fascinated by the myriad of techniques constantly under development for creating perfectly clear ice cubes, I also understand that every drinker is not always interested in taking the often painstaking steps required for the perfect crystal ball of ice. However, that doesn't mean they aren't interested in bringing fun, whimsy, and elegance to their cocktail parties.
The high-quality silicone ice ball molds from Tovoo make creating perfect ice spheres easy. What I like most about these are the fact they are stackable, and don't take up a ton of space in the freezer. The large sphere with greater surface area means that the ice will melt slower, leaving you to enjoy your drink longer without getting watered down. A personal favorite is the Rum Old Fashioned cocktail (picture above).
1.5 oz Puerto Rican Rum
.5 oz Jamaican Rum
.5 oz simple syrup (to taste)
Dash bitters (Angostura)