I think it helps to make syrup from the sugar first. Then when you add the sugar, you are pouring in a liquid instead of a powder, and I think that triggers foaming less. You can also drink it sooner with less shaking needed because it's easier to dissolve.
To make "simple syrup" just mix...
In France some years ago I found a dark n/a beer called "Tortel Brune". It was amazingly much better than any n/a beer I've ever had in the US. Basically the n/a beers in the us are made from brews that didn't have anything going for them to begin with other than alcohol, so without the...