My first drink was the Campari & Soda, using dehydrated Campari powder. It should be essentially non-alcoholic as the alcohol burns off long before the water before it becomes solid.
After a few tries to get the ratios right, here's what works.:
Take a 3-4 ounce glass of soda water,
add a tablespoonfull of dehydrated Campari powder,
and 1/2 teaspoon of 2:1 simple syrup. I found that 1:1 added the sweetness necesary that made it taste like Campari again, but it missed the syrupyness that makes Campari Campari.
It also lacks the brightness of Campari, and an expressed orange peel fixed that right up, so don't forget that even though it's not in the picture.
The Solid Liquids Project index is at this link.