One of the nicer treats I got in Italy last year was lemon soda. It’s ridiculously easy to make yourself: two ounces of simple syrup, four ounces of lemon juice, and six ounces of club soda, served over ice in a pint glass. Stir well (the syrup sinks to the bottom on its own) and enjoy. The lemon juice from concentrate grocery stores sell for cheap works just fine.
Why this stuff doesn’t sell here in the States I’ll never know. We like soda here, and we like lemonade.
I guess the hard part is making the simple syrup. Boil some water and dissolve one cup of granulated sugar in it at a time while stirring well. When no more sugar goes to solution, stop and let the liquid cool before bottling it. You’ll use this stuff for cocktails as well as soft drinks like lemon soda. Once you have it on hand, you’ll wonder what you ever did without it.