Soda water is an obvious way to add bubbles to a drink, but you can add carbonation, flavour and more alcohol if you swap it out for beer. Photo by Allagash Brewing.
Epicurious suggests adding a good lager to one of my favourite simple cocktails, the Americano (equal parts Campari and sweet vermouth, usually topped with carbonated water) but the options are only limited by your imagination. In addition to the Beer Americano, I'll also be making a Beer Aperol Spritz (Beerperol Spritz?), with a nice sour or Gose, and I suggest you do the same.
Beer Americano [Epicurious]