One thing you might find helpful is to link the carbs to a real world measure.
For instance, one teaspoon of sugar is 4g. From that, you can quickly start working out what's good and bad.
For instance, with the drink you posted about, that's 0.3g per 100ml. One bottle is prob about 500ml, which means the entire bottle contains 1.5g of carbs (0.3 x 5).
That's less than half a teaspoon of sugar across the entire bottle. Doesn't sound too bad, eh?
Compare that with Coke, which is about 10g per 100ml. Therefore, 500ml of Coke would have 50g of carbs in it - which would be the equivalent of 12 and a half teaspoons of sugar!
See what a difference it makes when you start thinking in teaspoons?
What you should always do is look at the actual amount being eaten, rather than simply the 100ml figure (the 100ml figure can help you work that out). For instance, ketchup contains more carbs per 100ml than Coke, if I recall correctly. But the total amount you might have on your plate would probably only be teaspoon or so, meaning that only a fraction of a teaspoon of sugar has been added to your plate.
The other thing to add to this is that ALL carbs count. Most fruit drinks contain as much sugar in them as Coke. There's usually a disclaimer on the bottle saying those are 'naturally occurring sugars'. Unfortunately, the human body does not differentiate between 'naturally occurring' sugars and added ones - it's all just sugar as far as your body is concerned. By way of comparison, it's a bit like thinking bacon isn't 'really' fatty, because the fat naturally occurs in the pig!
So, no matter how tempting it may be, always count all the carbs that are going in, even the 'natural' ones.