Generally speaking, punchy fruit flavours work best, but if you like the taste of something, give it a whirl and see how it turns out! You’ll be selecting the ingredients for flavour alone, so don’t worry about the sugar content of what you intend to ferment – your yeast will get all the fuel it needs from the sugar in our recipes.
One point to consider is adding some sharpness to help produce a balanced drink. Unless you are fermenting something super-citrussy, it’s advisable to drop in some lemon juice or zest to raise the acidity – just remember, though, that white lemon pith will impart unwanted bitterness, so be careful not to introduce any into the mix.