Quite refreshing on a hot, humid day, when prepare using the Parisian Technique.
Lacking a proper absinthe fountain, I filled a standard hard "BPA-Free" water bottle with ice and added cold water. Didn't work as well as the soft water bottle I used last year, but which is now standing by to top off the cat's drinking fountain, AKA table-top water feature. (You want a dribble, not a torrent...)
Note that, since the first of these posts, we have acquired a couple of proper absinthe spoons, and even a couple of absinthe glasses. With this glass design (above) you fill the "bulb" with absinthe and simply top off with the ice water.