I strongly recommend you learn to count carbs (sign up for a DAFNE course if you can, but in the meantime you can look at food labels or on the internet and figure out how many carbohydrates are in what you eat, taking portion size into account).
In the beginning it's easiest to aim for a consistent amount of carbs day to day, i.e. eat a similar amount of carbs for breakfast as you did for breakfast yesterday, etc. Once things stabilise you can learn how to be more flexible.
Carb counting makes it a lot easier to work out desserts and snacks. Certain treats are quite variable in their sugar content, particularly cakes and slices and the like, as they can be similar in appearance, size and weight but have significantly different sugar content. (By the way, the amount of carbs in a food is basically equal to the amount of sugar in it plus the amount of starch.)
Squares of chocolate are high in sugar but are still pretty good, as it's easy to get the same amount every time (stick with the same brand and count the squares!) and the fat in the chocolate slows down absorption. (This means chocolate is BAD for hypo treatment as it works too slowly.)
Fruit is great and tends to be fairly consistent if you have the same amount. Strawberries are fantastic because they are surprisingly low in carbs. I love dates. Try a date and some mixed berries in natural yoghurt (but don't forget that dairy products contain carbs too).
Snacking on salad is a great idea as greens contain essentially no carbs.
All the best!